# WhichCalc > Free online calculator catalog with 391 tools across finance, health, math, lifestyle, marketing, exams, and social-giving topics. Every calculator runs entirely in the browser with no signup, no tracking on the calculation itself, and instant results. WhichCalc covers the calculators US users search for most: BMI, mortgage, paycheck, calorie/TDEE, tip, GPA, compound interest, and many more. Each page includes the formula, worked examples, an educational explanation, and a FAQ section so the result is verifiable, not a black box. ## Category Hubs - [Finance Calculators](https://whichcalc.com/finance-calculators): 142 tools. Mortgage, tax, investment, retirement, loans, and personal finance planning. - [Health & Fitness Calculators](https://whichcalc.com/health-calculators): 74 tools. BMI, TDEE, body fat, pregnancy, heart rate, kidney, cholesterol, and fitness tools. - [Math & Statistics Calculators](https://whichcalc.com/math-calculators): 60 tools. Algebra, calculus, statistics, geometry, unit conversion, and STEM formulas. - [Lifestyle & Home Calculators](https://whichcalc.com/lifestyle-calculators): 92 tools. Home improvement, auto, pets, cooking, travel, events, and everyday planning. - [Religion & Social Giving Calculators](https://whichcalc.com/religion-social-calculators): 6 tools. Zakat, tithe, tzedakah, religious dates, and social giving planning. - [Marketing Calculators](https://whichcalc.com/marketing-calculators): 6 tools. CPM, creator earnings, SEO snippets, AI ROI, and token cost planning. - [Exam & Grade Calculators](https://whichcalc.com/exam-calculators): 4 tools. GPA, final grade targets, digital SAT scoring, and ACT superscore planning. ## Most Popular Calculators - [Mortgage Calculator](https://whichcalc.com/mortgage-calculator): Calculate monthly mortgage payment (PITI), full amortization schedule, PMI drop-off, and extra payment savings. - [Paycheck Calculator (Take-Home Pay)](https://whichcalc.com/paycheck-calculator): Calculate US take-home pay after federal income tax, Social Security, Medicare, and state income tax. Supports pre-tax 401(k), HSA, and health insurance. - [Online BMI Calculator (Adults)](https://whichcalc.com/bmi-calculator): Calculate your Body Mass Index (BMI) for adults. Get your BMI category, health risk level, and personalized recommendations. Free, instant, no signup. - [Time Card / Timesheet Calculator](https://whichcalc.com/time-card-calculator): Calculate weekly work hours from clock-in / clock-out times, lunch breaks, regular vs overtime hours under FLSA, and gross weekly pay. - [Compound Interest Calculator](https://whichcalc.com/compound-interest-calculator): Project investment growth with compound interest, regular contributions, multiple compound frequencies, and inflation adjustment. - [Auto Loan Calculator](https://whichcalc.com/auto-loan-calculator): Calculate auto loan monthly payment with down payment, trade-in, sales tax, fees, and full amortization schedule. - [Love Calculator (Name Compatibility)](https://whichcalc.com/love-calculator): A fun, just-for-laughs compatibility test based on two names with deterministic scoring plus the classic F.L.A.M.E.S schoolyard game. - [Tip Calculator](https://whichcalc.com/tip-calculator): Calculate tip and total bill with bill splitting, service quality presets, and a country-by-country tipping guide. - [Snow Day Calculator](https://whichcalc.com/snow-day-calculator): Estimate the probability your school will be closed based on forecast snow, temperature, region, school type, day of week, and storm timing. - [401(k) Retirement Calculator](https://whichcalc.com/401k-calculator): Project your 401(k) retirement balance with employer match, IRS contribution limits, and inflation-adjusted today’s dollars. - [Final Grade Calculator](https://whichcalc.com/final-grade-calculator): Find exactly what score you need on the final exam to hit your target letter grade for the class. Breakpoints for A, A-, B, C, and D shown side by side. - [Square Footage Calculator](https://whichcalc.com/square-footage-calculator): Calculate square footage of one or many rooms in feet, inches, yards, or meters. Includes flooring cost, waste allowance, and paint coverage estimates. ## Finance Calculators Hub: [Finance Calculators](https://whichcalc.com/finance-calculators) - [Mortgage Calculator](https://whichcalc.com/mortgage-calculator): Calculate monthly mortgage payment (PITI), full amortization schedule, PMI drop-off, and extra payment savings. - [Paycheck Calculator (Take-Home Pay)](https://whichcalc.com/paycheck-calculator): Calculate US take-home pay after federal income tax, Social Security, Medicare, and state income tax. Supports pre-tax 401(k), HSA, and health insurance. - [Time Card / Timesheet Calculator](https://whichcalc.com/time-card-calculator): Calculate weekly work hours from clock-in / clock-out times, lunch breaks, regular vs overtime hours under FLSA, and gross weekly pay. - [Compound Interest Calculator](https://whichcalc.com/compound-interest-calculator): Project investment growth with compound interest, regular contributions, multiple compound frequencies, and inflation adjustment. - [Auto Loan Calculator](https://whichcalc.com/auto-loan-calculator): Calculate auto loan monthly payment with down payment, trade-in, sales tax, fees, and full amortization schedule. - [401(k) Retirement Calculator](https://whichcalc.com/401k-calculator): Project your 401(k) retirement balance with employer match, IRS contribution limits, and inflation-adjusted today’s dollars. - [Net Worth Calculator](https://whichcalc.com/net-worth-calculator): Track assets minus liabilities. Compare your net worth to US median wealth by age (2022 Fed SCF data) and the classic "millionaire next door" target. - [US Federal Tax Bracket Calculator 2026](https://whichcalc.com/tax-bracket-calculator): Calculate US Federal income tax (10-37% brackets), UK Income Tax, or custom progressive brackets. See marginal rate, effective rate, and take-home pay. - [High-Yield Savings Account (HYSA) Calculator](https://whichcalc.com/hysa-calculator): Project HYSA growth at today's top APYs (~4.0-4.5%), compare to traditional savings, and see after-tax interest with federal and state tax rates. - [Roth IRA Calculator](https://whichcalc.com/roth-ira-calculator): Estimate tax-free Roth IRA growth, MAGI phase-out limits, and the Roth advantage over a taxable brokerage account. - [Debt Payoff Calculator (Snowball vs Avalanche)](https://whichcalc.com/debt-payoff-calculator): Compare the Snowball (smallest balance first) and Avalanche (highest APR first) debt strategies. Payoff dates, total interest, and the cost of paying minimums only. - [Social Security Benefits Calculator](https://whichcalc.com/social-security-calculator): Estimate your monthly Social Security retirement benefit using SSA bend points, your Full Retirement Age, and claim age 62-70. - [US Sales Tax Calculator](https://whichcalc.com/us-sales-tax-calculator): Calculate US sales tax by state with local rate override, forward and reverse modes, and tax-exempt support. - [Mortgage Affordability Calculator](https://whichcalc.com/mortgage-affordability-calculator): Calculate the maximum house price you can afford (28/36 rule, DTI), stress test scenarios, and hidden home ownership costs. - [FIRE Calculator (Financial Independence, Retire Early)](https://whichcalc.com/fire-calculator): Calculate your FIRE number using the 4% rule, years to FIRE, savings rate impact, and Coast FIRE for early retirement planning. - [Loan & Interest Calculator](https://whichcalc.com/loan-calculator): Calculate loan installments using flat, annuity, and declining balance methods. Simulate borrowing capacity. - [Investment & Compound Interest Calculator](https://whichcalc.com/investment-calculator): Simulate investment growth with compound interest and regular contributions. Includes year-by-year projections. - [Overtime Pay Calculator](https://whichcalc.com/overtime-pay-calculator): Track weekly hours and compute regular, overtime (1.5x), and double-time pay under US FLSA and state daily-OT rules. - [Tax Refund Calculator (2026 IRS)](https://whichcalc.com/tax-refund-calculator): Estimate your 2026 federal tax refund or amount owed. Compares year-to-date withholding against tax liability after deductions and credits. - [Hourly to Salary Converter](https://whichcalc.com/hourly-to-salary-calculator): Convert between hourly pay and annual salary. Adjusts for hours per week, weeks per year, PTO, and overtime. - [CD Calculator (Certificate of Deposit)](https://whichcalc.com/cd-calculator): Project CD maturity value, see early-withdrawal penalty impact, and compare CD returns to a high-yield savings account over the same period. - [VA Disability Calculator](https://whichcalc.com/va-disability-calculator): Calculate VA combined disability rating using the official "whole person" formula. Shows rounded rating and 2026 monthly compensation. - [RMD Calculator (Required Minimum Distribution)](https://whichcalc.com/rmd-calculator): Calculate IRS Required Minimum Distribution from a Traditional IRA or 401(k) using the 2026 Uniform Lifetime Table. - [HELOC Calculator (Home Equity Line of Credit)](https://whichcalc.com/heloc-calculator): Estimate maximum HELOC from home value, mortgage balance, and CLTV cap. Interest-only draw payments and full amortizing repayment. - [HSA Calculator (Health Savings Account)](https://whichcalc.com/hsa-calculator): Project HSA growth as a stealth IRA with triple tax savings: pre-tax contributions, tax-free growth, tax-free medical withdrawals. - [BAH Calculator (Basic Allowance for Housing)](https://whichcalc.com/bah-calculator): Estimate 2026 Basic Allowance for Housing by pay grade, dependents, and ZIP cost zone. Includes total compensation stack. - [Credit Card Payoff Calculator](https://whichcalc.com/credit-card-payoff-calculator): See how long to pay off a credit card and total interest. Compare minimum-only vs extra payment and model intro 0% APR transfers. - [Mileage Reimbursement Calculator (IRS)](https://whichcalc.com/mileage-calculator): Calculate IRS-standard mileage reimbursement for business, medical, charitable, and military moving travel. 2026 rates included. - [Amortization Calculator (Loan Schedule)](https://whichcalc.com/amortization-calculator): Full amortization schedule for any fixed-rate loan. See monthly P+I, total interest, payoff time, and savings from extra payments. - [Annual Income Calculator](https://whichcalc.com/annual-income-calculator): Convert hourly, daily, weekly, biweekly, semi-monthly, or monthly pay into annual income, plus a rough 2026 federal tax estimate. - [Annuity Calculator (Present & Future Value)](https://whichcalc.com/annuity-calculator): Calculate PV, FV, or payment of an annuity. Handles ordinary vs annuity-due and annual, quarterly, or monthly compounding with year-by-year accumulation table. - [Dividend Calculator (Yield, DRIP & Growth)](https://whichcalc.com/dividend-calculator): Project dividend income, DRIP compounding, and yield-on-cost over time with US qualified-dividend tax handling. - [Future Value Calculator (TVM)](https://whichcalc.com/future-value-calculator): Project the future value of a lump sum plus recurring contributions using the time value of money formula with six compounding frequencies and annuity-due or ordinary-annuity timing. - [Gold Calculator (Weight, Purity & Value)](https://whichcalc.com/gold-calculator): Calculate the melt value of gold jewelry, coins, or scrap from weight and karat purity. Estimates pure gold content, spot melt value, and a typical scrap-dealer offer. - [Mortgage Payoff Calculator (Extra Payments)](https://whichcalc.com/mortgage-payoff-calculator): See how much sooner you can pay off your mortgage and how much interest you can save by adding extra principal each month, a one-time lump sum, or switching to biweekly payments. - [Personal Loan Calculator](https://whichcalc.com/personal-loan-calculator): Estimate monthly payment, total interest, and effective APR on a fixed-rate US personal loan, with credit-tier scenarios and origination-fee math. - [Rent Affordability Calculator (28% & 30% Rule)](https://whichcalc.com/rent-calculator): How much rent can you afford? Applies the 28%, 30%, or 40% rule to gross income and estimates net take-home after taxes, with a traffic-light verdict on rent-to-net ratio. - [FHA Loan Calculator (3.5% Down + MIP)](https://whichcalc.com/fha-loan-calculator): Estimate FHA mortgage with UFMIP financed into the loan, monthly MIP, and a side-by-side comparison to conventional 20% down. - [APR Calculator (APR ↔ APY + True Loan APR)](https://whichcalc.com/apr-calculator): Convert APR ↔ APY at any compounding frequency, plus true APR on a loan after fees and points (Regulation Z disclosure). - [Boat Loan Calculator](https://whichcalc.com/boat-loan-calculator): Monthly payment, total interest, and amortization for a US marine loan. Includes down payment, trade-in, sales tax, and dealer fees. - [Margin Calculator (Profit, Markup, Pricing)](https://whichcalc.com/margin-calculator): Profit margin, markup, and selling price for any product. Four modes including markup-to-margin conversion and cost ceiling from target margin. - [Car Affordability Calculator (20/4/10 Rule)](https://whichcalc.com/car-affordability-calculator): Max car sticker price you can afford from income, down payment, trade-in, insurance, sales tax, DTI ratio, and the 20/4/10 rule. - [Bitcoin ETF Return Calculator](https://whichcalc.com/bitcoin-etf-return-calculator): Model your Bitcoin spot ETF returns, calculate expense ratio drag vs direct BTC ownership, and estimate after-tax gains for IBIT, FBTC, ARKB, and more. - [Federal Employee Severance Calculator](https://whichcalc.com/federal-job-loss-severance-calculator): Estimate RIF severance pay, VERA/VSIP buyout, and unemployment benefits for federal government employees laid off in 2025–2026 DOGE workforce reductions. - [Rent Increase Impact Calculator](https://whichcalc.com/rent-increase-impact-calculator): Analyze how a rent hike affects your monthly budget, rent-to-income ratio, and whether you cross the HUD cost-burdened threshold. - [Medigap Plan Cost Calculator](https://whichcalc.com/medigap-plan-cost-calculator): Compare Medicare Supplement (Medigap) plans G, N, F, and HDG — estimate your monthly premium and annual out-of-pocket vs Medicare Advantage. - [Estate Tax Exemption Calculator 2026](https://whichcalc.com/estate-tax-exemption-calculator): Calculate federal estate tax under OBBBA's new $15 million exemption (2026), including gifting strategies and portability for married couples. - [Small Business Tariff Cost Calculator](https://whichcalc.com/small-business-tariff-calculator): Estimate your small business's total annual tariff burden across multiple imported product lines and calculate revenue needed to maintain margins. - [Home Equity Loan Calculator](https://whichcalc.com/home-equity-loan-calculator): Calculate monthly payments, total interest, and combined LTV for a fixed-rate home equity loan — and see how much equity you can borrow against. - [Tariff Price Increase Calculator 2026](https://whichcalc.com/tariff-price-increase-calculator): Calculate how 2026 US import tariffs increase the cost of a specific product based on its country of origin, category, and your retail margin. - [Trump Account Child Savings Calculator](https://whichcalc.com/trump-account-calculator): Project how much a Trump Account (OBBBA 2026 child investment account) could grow to by age 18, including the $1,000 federal seed. - [Medicare IRMAA Calculator 2026](https://whichcalc.com/medicare-irmaa-calculator): Find out if your 2024 income triggers an IRMAA surcharge on your 2026 Medicare Part B and Part D premiums — and estimate your monthly cost. - [SALT Deduction Calculator 2026](https://whichcalc.com/salt-deduction-calculator): Calculate your 2026 state and local tax (SALT) deduction under the OBBBA's new $40,400 cap, with income-based phaseout for high earners. - [Section 179 Deduction Calculator (2026)](https://whichcalc.com/section-179-deduction-calculator): Section 179 lets businesses expense qualifying property up to $2.5M in 2026 (raised from $1.16M), with phase-out beginning at $4M of purchases. Heavy SUV (6,000+ lb GVWR) capped at ~$31K. - [Bonus Depreciation Calculator (100% Section 168k)](https://whichcalc.com/bonus-depreciation-calculator): OBBBA permanently restored 100% bonus depreciation under Section 168(k) for qualified property placed in service after January 19, 2025. Covers MACRS 20-year-or-less assets including vehicles, machinery, computer equipment. - [Hurricane / Named Storm Deductible Calculator](https://whichcalc.com/hurricane-deductible-calculator): Hurricane and named-storm deductibles in FL, TX, NC, SC, GA, MA, NJ, NY, MS, AL are a percentage of dwelling coverage (typically 2-5%), separate from your standard all-perils deductible. Computes out-of-pocket on damage. - [Single Income Budget Calculator (50/30/20 Solo)](https://whichcalc.com/single-income-budget-calculator): Modified 50/30/20 budget for single-income households: housing is harder to share, emergency fund must cover full income loss, no spouse income safety net. Sliders adjust for HCOL/LCOL metros. - [RAP vs PSLF Student Loan Payment Calculator](https://whichcalc.com/rap-vs-pslf-payment-calculator): Repayment Assistance Plan (RAP) starts July 2026 replacing SAVE. Compute monthly payment under RAP, IBR, PAYE, and Standard. Compare forgiveness pathway, PSLF eligibility, and total interest cost. - [QBI Deduction Calculator (Section 199A, 23%)](https://whichcalc.com/qbi-deduction-calculator): Section 199A qualified business income deduction for pass-through entities — raised to 23% in 2026 under OBBBA. SSTB phase-in: $200K single / $400K joint. Includes W-2 wage / UBIA limitation for higher earners. - [Senior Bonus Deduction Calculator (Age 65+)](https://whichcalc.com/senior-bonus-deduction-calculator): OBBBA gives taxpayers 65+ an additional $6,000 standard-deduction bonus on top of the existing age-65 add-on. Phase-out: $75K single / $150K MFJ MAGI. Stacks with the standard deduction. - [Car Loan Interest Deduction Calculator (OBBBA)](https://whichcalc.com/car-loan-interest-deduction-calculator): OBBBA allows up to $10,000 of new-car loan interest to be deducted, but only for vehicles assembled in the US (model year 2025+). Phase-out begins at $100K MAGI ($200K MFJ). Personal-use loan only. - [No Tax on Overtime Deduction Calculator](https://whichcalc.com/no-tax-on-overtime-calculator): OBBBA lets workers deduct overtime premium pay — up to $12,500 single / $25,000 joint — from federal taxable income. Half-time portion of FLSA overtime only; phase-out matches the tips deduction. - [No Tax on Tips Deduction Calculator (OBBBA)](https://whichcalc.com/no-tax-on-tips-calculator): Estimate the OBBBA "no tax on tips" deduction — up to $25,000 of qualifying tip income deducted from taxable income, phased out above $150K (single) / $300K (MFJ). Federal tax savings depend on your marginal bracket. - [Heat Pump Tax Credit Calculator (IRA)](https://whichcalc.com/heat-pump-tax-credit-calculator): 30% federal credit up to $2,000/year on qualifying heat pumps under IRA. Includes IRS Form 5695, AHRI listing requirement, and state stacking (e.g., HEEHRA rebate). - [Pet Insurance Cost Calculator](https://whichcalc.com/pet-insurance-cost-calculator): Monthly premium + deductible + reimbursement % across major US pet insurers (Trupanion, Healthy Paws, Embrace, Lemonade). Includes annual cap analysis. - [Auto Insurance Cost Calculator](https://whichcalc.com/auto-insurance-cost-calculator): Estimate annual auto insurance from state, driver age, credit tier, vehicle type, and coverage selection. 2026 US averages — premiums rose 24% YoY through 2025. - [Home Insurance Cost Calculator](https://whichcalc.com/home-insurance-cost-calculator): Estimate annual home insurance premium by state, home value, age of home, deductible, and risk zone (FL/CA/TX climate exposure). 2026 US averages plus FAIR Plan reference. - [Tariff Impact Calculator (Section 232/301)](https://whichcalc.com/tariff-impact-calculator): How much does a US tariff add to import price? Computes landed cost including HTS duty rate, MPF, HMF, and any Section 232 (steel/aluminum) or Section 301 (China) tariffs. - [Tax Loss Harvesting Calculator](https://whichcalc.com/tax-loss-harvesting-calculator): Sell losing positions to offset capital gains plus up to $3K of ordinary income; carry the rest forward. Watch the wash-sale rule (30 days). Compute the savings versus holding to recover. - [Crypto Cost Basis Calculator (FIFO/LIFO/HIFO)](https://whichcalc.com/crypto-cost-basis-calculator): Compute crypto cost basis using FIFO (default), LIFO, or HIFO across multiple lots. HIFO usually minimizes capital gains; FIFO is required by some exchanges. New IRS 1099-DA in 2026. - [Treasury Bill Ladder Calculator](https://whichcalc.com/treasury-bill-ladder-calculator): Stagger T-bill maturities (4, 8, 13, 17, 26, 52 weeks) for steady income with rolling reinvestment. Computes expected monthly cash, weighted yield, and state-tax-free advantage. - [Inherited IRA Calculator (10-Year Rule)](https://whichcalc.com/inherited-ira-calculator): SECURE Act 2020 forces most non-spouse beneficiaries to fully withdraw the account within 10 years. Compute the year-by-year withdrawal that minimizes lifetime tax (front-load, level, back-load strategies). - [Daycare vs Salary Calculator](https://whichcalc.com/daycare-vs-salary-calculator): Does it pay to work when daycare costs $1,500-$3,000/mo? Compute net take-home after taxes minus childcare, transit, and lost retirement match. - [HSA Contribution Limit Calculator (2026)](https://whichcalc.com/hsa-contribution-limit-calculator): Compute your 2026 HSA contribution headroom: $4,400 individual / $8,750 family + $1,000 catch-up at 55+. Pro-rates partial-year HDHP coverage and applies the last-month rule. - [Mega Backdoor Roth Calculator](https://whichcalc.com/mega-backdoor-roth-calculator): High earners use the mega backdoor to push up to $46K into Roth via after-tax 401(k) contributions + in-plan conversion. Compute headroom available given existing contributions and employer match. - [Mortgage Rate Buydown Calculator (2-1 / 3-2-1)](https://whichcalc.com/mortgage-rate-buydown-calculator): Builders and sellers often offer 2-1 or 3-2-1 temporary rate buydowns. Compute year-by-year payment + escrow amount needed to fund the buydown. - [Solar Tax Credit Calculator (30% ITC)](https://whichcalc.com/solar-tax-credit-calculator): Compute the 30% federal residential clean energy credit on a solar PV system through 2032. Includes panels, inverter, battery storage, installation labor, and state-credit stacking. - [EV Federal Tax Credit Calculator ($7,500)](https://whichcalc.com/ev-federal-tax-credit-calculator): Check eligibility for the $7,500 federal EV tax credit (IRA 2022): income limits ($150K single, $300K MFJ), MSRP cap ($55K cars / $80K SUVs+trucks), battery sourcing, North American assembly. - [Rent Burden Calculator (30% Rule)](https://whichcalc.com/rent-burden-calculator): Are you rent-burdened? The 30% rule says housing should not exceed 30% of gross income; severely cost-burdened is 50%+. HUD uses these thresholds for affordability research. - [W-4 Withholding Calculator](https://whichcalc.com/w-4-withholding-calculator): Estimate federal income tax withholding from your paycheck under the 2026 W-4 form. Calibrate extra withholding or adjustments so you avoid a refund (interest-free loan to the IRS) or an under-withholding penalty. - [SIP Calculator (Systematic Investment Plan)](https://whichcalc.com/sip-calculator): Project future value of regular monthly mutual-fund contributions with expected annual return. Includes step-up SIP (annual contribution increase). - [Life Insurance Needs Calculator (DIME)](https://whichcalc.com/life-insurance-needs-calculator): Calculate term life insurance needs using DIME method (Debt + Income replacement + Mortgage + Education) plus final expenses. - [Annuity Payout Calculator](https://whichcalc.com/annuity-payout-calculator): Calculate monthly/annual payouts for an immediate fixed annuity (SPIA) based on premium, age, and current annuity rates. - [RSU Tax Calculator](https://whichcalc.com/rsu-tax-calculator): Calculate federal, state, FICA, and AMT exposure on Restricted Stock Units at vest and sale. Captures the under-withholding gap most RSU recipients miss. - [Employee Stock Options Calculator](https://whichcalc.com/stock-options-calculator): Value employee stock options (ISOs/NSOs) at exercise and sale. Includes spread, ordinary income vs capital gains, and AMT exposure for ISOs. - [Bond Price Calculator](https://whichcalc.com/bond-price-calculator): Compute bond price from coupon rate, market yield, face value, and years to maturity. Shows premium/par/discount status. - [Yield to Maturity Calculator (YTM)](https://whichcalc.com/ytm-calculator): Compute the total annualized yield on a bond held to maturity. Includes coupon income plus any premium/discount accretion. Newton-Raphson solver. - [Inflation-Adjusted Return Calculator](https://whichcalc.com/inflation-adjusted-return-calculator): Convert nominal investment return to real (inflation-adjusted) using Fisher equation. Real Return = (1+nominal)/(1+inflation) − 1. - [Millionaire Calculator](https://whichcalc.com/millionaire-calculator): When will you reach $1 million? Project the year based on current portfolio, monthly contribution, and expected return (real or nominal). - [50/30/20 Budget Calculator](https://whichcalc.com/budget-503020-calculator): Allocate after-tax income into 50% needs, 30% wants, 20% savings/debt. Popularized by Sen. Elizabeth Warren in All Your Worth. - [Savings Rate Calculator (FIRE)](https://whichcalc.com/savings-rate-calculator): Savings rate = (income − spending) / income. Projects years to financial independence at your current pace using the 4% safe withdrawal rule. - [Debt-to-Income Ratio Calculator (DTI)](https://whichcalc.com/debt-to-income-calculator): DTI = total monthly debt / gross monthly income. Mortgage lenders typically cap at 43-50%. Front-end (housing only) and back-end (all debt) shown. - [Refinance Break-Even Calculator](https://whichcalc.com/refinance-break-even-calculator): How many months until refi savings recoup closing costs. If you sell or refi again before break-even, you lose money. - [Cash-on-Cash Return Calculator](https://whichcalc.com/cash-on-cash-return-calculator): Annual pre-tax cash flow / total cash invested. Real-estate investor metric that captures leverage effect; 8-12% typical, 12%+ strong. - [Gross Rent Multiplier Calculator (GRM)](https://whichcalc.com/gross-rent-multiplier-calculator): GRM = Property Price / Annual Gross Rent. Quick rental-property screening metric (ignores expenses). Lower is better; 8-12 typical, 4-7 strong cash-flow. - [Cap Rate Calculator (Real Estate)](https://whichcalc.com/cap-rate-calculator): Capitalization rate = NOI / Purchase Price. Quick yield comparison for rental properties. Typical 2026 US cap rates: 4-6% prime, 6-10% mid-market, 10%+ value-add. - [House Affordability Calculator](https://whichcalc.com/house-affordability-calculator): Calculate the maximum home price you can afford using the 28/36 rule (max 28% of gross income on housing, 36% on total debt). - [Rent vs Buy Calculator](https://whichcalc.com/rent-vs-buy-calculator): Find your break-even time horizon for buying vs renting. Accounts for opportunity cost of down payment, maintenance, appreciation, and tax benefits. - [Closing Costs Calculator](https://whichcalc.com/closing-costs-calculator): Estimate total closing costs for a home purchase (typically 2-5% of price). Includes lender fees, title, escrow, transfer tax, and recording fees. - [USDA Loan Calculator](https://whichcalc.com/usda-loan-calculator): Calculate USDA Rural Development loan payments. 0% down available for eligible rural properties; includes 1% upfront guarantee fee and 0.35% annual fee. - [VA Loan Calculator](https://whichcalc.com/va-loan-calculator): Calculate VA mortgage payments with 0% down option. Includes funding fee tiers based on service type and down payment, plus PITI breakdown. - [Jumbo Loan Calculator](https://whichcalc.com/jumbo-loan-calculator): Calculate monthly payments on a jumbo mortgage (loans above the conforming limit, $806,500 in 2026 for most areas). Higher rates and stricter requirements apply. - [PITI Calculator (Principal + Interest + Taxes + Insurance)](https://whichcalc.com/piti-calculator): Calculate your total monthly mortgage payment: Principal + Interest + property Taxes + homeowners Insurance + optional HOA and PMI. - [Effective Tax Rate Calculator](https://whichcalc.com/effective-tax-rate-calculator): Find your effective federal tax rate (total tax / gross income) vs marginal rate, with full bracket breakdown for 2026. - [Quarterly Estimated Tax Calculator](https://whichcalc.com/quarterly-tax-calculator): Compute IRS quarterly estimated tax payments for freelancers and self-employed. Includes safe-harbor rules and due dates (Apr 15, Jun 15, Sep 15, Jan 15). - [Traditional vs Roth IRA Calculator](https://whichcalc.com/traditional-vs-roth-calculator): Compare projected retirement balances and after-tax income for Traditional vs Roth IRA contributions based on your current and expected tax brackets. - [Roth Conversion Calculator](https://whichcalc.com/roth-conversion-calculator): Estimate the tax cost and break-even time for converting traditional IRA/401(k) funds to a Roth, including the pro-rata rule check. - [529 College Savings Plan Calculator](https://whichcalc.com/529-savings-plan-calculator): Project the future value of a 529 college savings plan with monthly contributions, accounting for tuition inflation and tax-free growth. - [Savings Goal Calculator](https://whichcalc.com/savings-goal-calculator): Find out how much you need to save monthly to hit any savings goal by a target date, with optional interest compounding. - [Emergency Fund Calculator](https://whichcalc.com/emergency-fund-calculator): Calculate the right size for your emergency fund (3-12 months of expenses) and how long it will take to save it at your current pace. - [1099 vs W-2 Calculator](https://whichcalc.com/1099-vs-w2-calculator): Compare a W-2 employee offer against an equivalent 1099 contractor / freelance role apples-to-apples, including SE tax, own health insurance, and unbillable hours. - [Self-Employment Tax Calculator (SECA)](https://whichcalc.com/self-employment-tax-calculator): Estimate the 15.3% Self-Employment tax for freelancers and contractors. Includes the deductible half adjustment and quarterly estimate. - [Child Tax Credit Calculator 2026](https://whichcalc.com/child-tax-credit-calculator): Estimate your federal Child Tax Credit (CTC) and Credit for Other Dependents (ODC) for the 2026 tax year, including the refundable Additional CTC. - [Capital Gains Tax Calculator (2026)](https://whichcalc.com/capital-gains-tax-calculator): Estimate federal capital gains tax on stock, crypto, or real estate sales. Short vs long-term, plus 3.8% NIIT for high earners. - [Biweekly Mortgage Calculator](https://whichcalc.com/biweekly-mortgage-calculator): See how much time and interest you save by paying half your mortgage payment every 2 weeks (26 half-payments/year = 13 monthly equivalents). - [ARM Mortgage Calculator (Adjustable Rate)](https://whichcalc.com/arm-mortgage-calculator): Compare the introductory fixed-rate payment of an Adjustable-Rate Mortgage against the worst-case adjusted payment after rate caps. Supports 5/6, 7/6, 10/6 ARMs. - [Mortgage Points Calculator (Break-Even)](https://whichcalc.com/mortgage-points-calculator): Compute the break-even point on buying discount points for a lower mortgage rate. Includes after-tax break-even calculation. - [PMI Calculator (Private Mortgage Insurance)](https://whichcalc.com/pmi-calculator): Estimate the monthly Private Mortgage Insurance premium on a conventional loan and find out how long until you can request PMI removal at 80% LTV. - [Student Loan Calculator (Standard vs Income-Driven)](https://whichcalc.com/student-loan-calculator): Compare the standard 10-year repayment against an income-driven plan (SAVE/PAYE/IBR-style). Shows monthly payment, total interest, and balance forgiven at year 20. - [Down Payment Calculator](https://whichcalc.com/down-payment-calculator): Calculate your home down payment target and how long it will take to save it at your current savings rate. PMI-avoidance check included. - [Simple Interest Calculator](https://whichcalc.com/simple-interest-calculator): Compute interest using I = P × r × t (no compounding). Used for short-term consumer loans, T-bills, and savings without compounding. - [Salary Calculator (Gross to Net)](https://whichcalc.com/salary-calculator): Convert annual gross salary to take-home pay across pay periods. Computes federal tax, FICA, state tax, and pre-tax 401(k) deductions. - [Federal Income Tax Calculator 2026](https://whichcalc.com/income-tax-calculator): Estimate federal income tax for 2026 using the projected IRS brackets and standard deduction. Supports all four filing statuses and pre-tax 401(k)/HSA adjustments. - [Side Hustle & Multi-Income Calculator](https://whichcalc.com/side-hustle-calculator): Track multiple income streams (gig economy, freelance, 1099), profitability per hour, self-employment tax estimates, and income goal planner. - [Crypto Gas Fee Calculator (Gwei & Layer 2)](https://whichcalc.com/crypto-gas-fee-calculator): Calculate Ethereum gas fees in Gwei/USD, Layer 2 comparison (Arbitrum/Optimism/Polygon), and gas optimization tips. - [Rental Property ROI Calculator](https://whichcalc.com/rental-property-roi-calculator): Calculate Cap Rate, Cash-on-Cash Return, 5/10-year total ROI, and Airbnb vs long-term rental comparison. - [Salary Negotiation & Total Compensation Calculator](https://whichcalc.com/salary-negotiation-calculator): Calculate total compensation (base+bonus+equity+benefits), counter offer math, raise vs job switch, and freelance hourly rate. - [Loan Refinance Calculator](https://whichcalc.com/loan-refinance-calculator): Calculate refinance savings, break-even point, cash-out refi, and term vs rate option comparisons. - [Crypto Staking & DeFi Yield Calculator](https://whichcalc.com/crypto-staking-calculator): Calculate ETH/SOL/ADA/DOT staking rewards, auto-compound vs manual, staking vs HODL comparison, and DeFi yield strategies. - [Asset Depreciation Calculator](https://whichcalc.com/depreciation-calculator): Calculate asset depreciation with 4 methods: straight-line, declining balance, SYD, and units of production. Includes IAS 16 reference. - [Sharia Mortgage Calculator](https://whichcalc.com/sharia-mortgage-calculator): Simulate Islamic mortgage with Murabahah, Musyarakah Mutanaqisah (MMQ), and IMBT contracts — comparison with conventional mortgage. - [Subscription Tracker Calculator](https://whichcalc.com/subscription-tracker-calculator): Track monthly subscriptions, compare annual vs monthly billing, 5-year cost projection, and identify subscriptions to cancel. - [NPV & IRR Calculator](https://whichcalc.com/npv-irr-calculator): Analyze investment feasibility with Net Present Value, Internal Rate of Return, Payback Period, and project comparison. - [ROI (Return on Investment) Calculator](https://whichcalc.com/roi-calculator): Calculate simple ROI, annualized ROI (CAGR), compare investments side by side, and plan target returns with projections. - [Currency Conversion Calculator](https://whichcalc.com/currency-converter): Convert between 15 major world currencies. Includes quick conversion tables and popular currency pairs. - [Profit Margin & Markup Calculator](https://whichcalc.com/profit-margin-calculator): Calculate profit margin, markup, and selling price from cost. Three calculation modes for business pricing. - [Forex Calculator (Pip, Lot, Margin)](https://whichcalc.com/forex-calculator): Calculate pip value, lot size, and margin requirements for forex trading. Supports various currency pairs and leverage settings. - [Break-Even Point (BEP) Calculator](https://whichcalc.com/break-even-calculator): Calculate your business break-even point in units and revenue. Includes contribution margin and margin of safety analysis. - [Retirement Fund Calculator](https://whichcalc.com/retirement-fund-calculator): Calculate how much you need for retirement and the monthly savings required to retire comfortably. - [Inflation Calculator](https://whichcalc.com/inflation-calculator): Calculate the impact of inflation on the value of money and purchasing power over time. Includes year-by-year projections. - [Stock Average Price Calculator](https://whichcalc.com/stock-average-calculator): Calculate average stock purchase price (average down/up), break-even price, and simulate profit/loss scenarios. - [Online Discount Calculator](https://whichcalc.com/discount-calculator): Calculate the price after single or stacked (double) discounts. Includes tax simulation and total savings breakdown. ## Health & Fitness Calculators Hub: [Health & Fitness Calculators](https://whichcalc.com/health-calculators) - [Online BMI Calculator (Adults)](https://whichcalc.com/bmi-calculator): Calculate your Body Mass Index (BMI) for adults. Get your BMI category, health risk level, and personalized recommendations. Free, instant, no signup. - [GLP-1 Weight Loss Calculator (Ozempic / Wegovy / Mounjaro / Zepbound)](https://whichcalc.com/glp-1-calculator): Project weight loss on Wegovy, Ozempic, Mounjaro, Zepbound, and Saxenda using STEP and SURMOUNT trial data. Monthly BMI trajectory and side effects. - [Calorie, BMR & TDEE Calculator](https://whichcalc.com/tdee-calculator): Calculate daily calorie needs, Basal Metabolic Rate (BMR), and Total Daily Energy Expenditure (TDEE) from your body data and activity level. Includes macros. - [Calorie Deficit Calculator (Diet)](https://whichcalc.com/calorie-deficit-calculator): Calculate your daily calorie target for weight loss. Includes weekly weight loss projections. - [Pregnancy Due Date Calculator](https://whichcalc.com/pregnancy-calculator): Calculate gestational age, estimated due date (EDD), and fetal development milestones based on your last menstrual period (LMP). - [One Rep Max Calculator (1RM)](https://whichcalc.com/one-rep-max-calculator): Estimate your one-rep max from a sub-max set. Compares Epley, Brzycki, Lander, Lombardi, Mayhew, O'Conner, and Wathan formulas. - [BAC Calculator (Blood Alcohol Content)](https://whichcalc.com/bac-calculator): Estimate Blood Alcohol Content from drinks using the Widmark formula. See US legal driving thresholds and hours until BAC reaches 0.00. - [Running Pace Calculator](https://whichcalc.com/running-pace-calculator): Calculate running pace, finish time, or distance. Includes training zones (easy, tempo, threshold, interval) and race predictions. - [ASCVD Risk Calculator](https://whichcalc.com/ascvd-risk-calculator): Estimate 10-year heart attack and stroke risk using ACC/AHA Pooled Cohort Equations. Guides who benefits from statin therapy. - [Conception Calculator](https://whichcalc.com/conception-calculator): Estimate when you conceived from due date, ultrasound dating, or last period. Shows conception window and fertile days. - [A1C Calculator (HbA1c to Average Glucose)](https://whichcalc.com/a1c-calculator): Convert HbA1c to estimated average glucose (eAG) and back. Includes ADA diabetes management category - normal, prediabetes, diabetes. - [Chronological Age Calculator (Years, Months, Days)](https://whichcalc.com/chronological-age-calculator): Find your exact age in years, months, and days from your date of birth to today or any target date. Includes total days lived, weeks, hours, days until next birthday, zodiac sign, and generation label. - [Creatinine Clearance Calculator (Cockcroft-Gault)](https://whichcalc.com/creatinine-clearance-calculator): Estimate creatinine clearance with the 1976 Cockcroft-Gault formula. Used on most FDA drug labels for renal dose adjustment. Supports mg/dL and umol/L, kg and lb, and IBW/AdjBW correction for obese patients. - [Peptide Reconstitution Calculator](https://whichcalc.com/peptide-calculator): Convert peptide vial size and bacteriostatic water volume into mg/mL concentration, mcg per insulin unit, units to draw per dose, doses per vial, and weeks of supply. Supports semaglutide, tirzepatide, BPC-157, TB-500, GHK-Cu, and retatrutide. - [Weight Loss Calculator (Deficit + Timeline)](https://whichcalc.com/weight-loss-calculator): Daily calorie target and target date from current and goal weight, Mifflin-St Jeor BMR, and activity multiplier. - [Macro Calculator (Carbs, Protein, Fat)](https://whichcalc.com/macro-calculator): Daily carbs, protein, and fat targets for any goal (cut, maintain, bulk, keto, high-protein, endurance). Uses Mifflin-St Jeor BMR + activity multiplier. - [Caffeine Calculator (Intake + Half-Life)](https://whichcalc.com/caffeine-calculator): Audit daily caffeine vs the 400 mg safe limit and model how much is still in your system after N hours using the 5-hour half-life. - [Water Intake Calculator (Daily Hydration)](https://whichcalc.com/water-intake-calculator): Daily water target in oz, liters, cups, and bottles, sized to bodyweight, activity, climate, and pregnancy status. - [Max Heart Rate Calculator (HRmax + Zones)](https://whichcalc.com/max-heart-rate-calculator): Maximum heart rate and 5 training zones from age. Choose Fox, Tanaka, Gulati, or Nes formula; Karvonen if you know resting HR. - [Zone 2 Heart Rate Training Calculator](https://whichcalc.com/zone2-heart-rate-calculator): Calculate your exact Zone 2 heart rate range for aerobic base building and all 5 training zones using the Karvonen or % max HR method. - [Longevity Score Calculator](https://whichcalc.com/longevity-score-calculator): Get a personalized longevity score (0–100) based on your lifestyle factors — smoking, exercise, sleep, diet, stress — and see your projected lifespan. - [Visceral Fat Level Estimator](https://whichcalc.com/visceral-fat-calculator): Estimate your visceral fat level (scale 1–59) from waist circumference and height using a CT-validated regression model. - [VO2 Max & Fitness Age Calculator](https://whichcalc.com/vo2max-fitness-age-calculator): Estimate your VO2 max from the Rockport walk test or Cooper run test, and calculate your cardiovascular fitness age vs population norms. - [GLP-1 Weight Loss Projection Calculator](https://whichcalc.com/glp1-weight-loss-calculator): Project your expected weight loss on Wegovy, Mounjaro, Ozempic, or Saxenda over 3–24 months using published clinical trial averages. - [Medicaid Work Requirement Calculator](https://whichcalc.com/medicaid-work-requirement-calculator): Check if you meet the new OBBBA 2026 Medicaid work requirement of 80 hours/month and whether you qualify for an exemption. - [ACA Subsidy Calculator 2026](https://whichcalc.com/aca-subsidy-cliff-calculator): Estimate your 2026 ACA marketplace subsidy and monthly premium after enhanced credits expired — based on income and family size. - [GLP-1 Out-of-Pocket Cost Calculator (Wegovy / Ozempic / Zepbound)](https://whichcalc.com/glp1-out-of-pocket-calculator): Monthly out-of-pocket for Wegovy, Ozempic, Mounjaro, Zepbound, or compounded semaglutide. Factors insurance tier (covered/not covered), deductible status, manufacturer savings card eligibility, July 2026 Medicare bridge. - [eGFR Calculator (CKD-EPI 2021)](https://whichcalc.com/creatinine-egfr-ckd-epi-calculator): Estimated GFR via the 2021 CKD-EPI equation (race-free, default standard for adults). Stages chronic kidney disease G1-G5. - [TDEE Zigzag Calorie Calculator](https://whichcalc.com/tdee-zigzag-calculator): Cycle daily calories above and below TDEE to hit a weekly target. Refeed days reduce metabolic adaptation during fat loss. - [Weight Percentile Calculator (Adult)](https://whichcalc.com/weight-percentile-calculator): Find your weight percentile vs the CDC NHANES adult population by age and sex. Better than BMI for comparing to peers. - [Anion Gap Calculator](https://whichcalc.com/anion-gap-calculator): Anion Gap = Na − (Cl + HCO₃). Used to diagnose metabolic acidosis. Normal 8-12. High AG suggests lactic acidosis, DKA, uremia. - [LDL Cholesterol Calculator](https://whichcalc.com/ldl-calculator): Calculate LDL cholesterol via Friedewald equation (LDL = Total − HDL − Triglycerides/5). Includes ACC/AHA risk categories. - [Pregnancy Trimester Calculator](https://whichcalc.com/pregnancy-trimester-calculator): Find current trimester and key milestone dates (end of trimester 1 at 13w 6d, trimester 2 at 27w 6d, full term at 39w-40w). - [Baby Formula Calculator](https://whichcalc.com/baby-formula-calculator): Calculate daily formula needs for infants 0-12 months based on weight (2.5 oz per lb/day or 150 ml per kg/day) and feeding frequency. - [Corrected Age Calculator (Preemies)](https://whichcalc.com/corrected-age-calculator): For premature babies: subtract weeks born early from chronological age. Pediatricians use corrected age for developmental milestones up to 2 years. - [Mean Arterial Pressure Calculator (MAP)](https://whichcalc.com/mean-arterial-pressure-calculator): MAP = (Systolic + 2×Diastolic) / 3. Average pressure during one cardiac cycle. Target ≥65 mmHg for organ perfusion; sepsis guidelines. - [Pulse Pressure Calculator](https://whichcalc.com/pulse-pressure-calculator): Pulse Pressure = Systolic − Diastolic BP. Wide PP (>60) suggests arterial stiffness; narrow PP (<25) suggests low cardiac output. - [Standard Drinks Calculator](https://whichcalc.com/standard-drinks-calculator): Convert any alcoholic beverage to US standard drinks (14 g pure alcohol). Compare against NIAAA low-risk guidelines (men: ≤14/wk, women: ≤7/wk). - [Pack Years Calculator](https://whichcalc.com/pack-years-calculator): Calculate smoking exposure in pack-years (packs per day × years smoked). USPSTF recommends lung cancer screening for 20+ pack-year history. - [DOTS Score Calculator (Powerlifting)](https://whichcalc.com/dots-score-calculator): DOTS replaced Wilks as the IPF standard in 2020. Compares powerlifting performance across body weights and genders. - [Wilks Score Calculator (Powerlifting)](https://whichcalc.com/wilks-score-calculator): Compare powerlifting strength across body weights using the Wilks coefficient. Total lifted × Wilks coefficient = score. Updated formula (Wilks 2020) available. - [Body Surface Area Calculator (BSA)](https://whichcalc.com/body-surface-area-calculator): Compute body surface area using Mosteller, Du Bois, and Haycock formulas. Used for chemotherapy dosing, burn assessment, and cardiac index. - [BMR Calculator (3 Formulas)](https://whichcalc.com/bmr-calculator): Estimate resting calorie burn using Mifflin-St Jeor (default), Harris-Benedict revised, and Katch-McArdle (uses lean body mass for highest accuracy). - [Waist-to-Height Ratio Calculator](https://whichcalc.com/waist-to-height-ratio-calculator): Compute waist-to-height ratio (WHtR), a better cardiovascular risk predictor than BMI for most adults. Keep waist under half your height. - [Army Body Fat Calculator (AR 600-9)](https://whichcalc.com/army-body-fat-calculator): Calculate body fat percentage using the US Army tape test per AR 600-9, including the 2024 simplified female method and age-band standards. - [Lean Body Mass Calculator](https://whichcalc.com/lean-body-mass-calculator): Estimate fat-free mass (LBM) using Boer, Hume, and James formulas. Useful for protein-intake targets and tracking body recomposition. - [Target Heart Rate Calculator (5 Zones)](https://whichcalc.com/target-heart-rate-calculator): Compute max heart rate and 5 training zones using the Karvonen method (heart-rate reserve) or simple percent-of-max. For cardio training and weight loss. - [Body Recomposition Calculator](https://whichcalc.com/body-recomposition-calculator): Plan simultaneous fat loss + muscle gain (recomp): macro plan, realistic expectations, timeline, and progress tracker. - [Sleep Coach Calculator (REM Stages)](https://whichcalc.com/sleep-coach-calculator): Analyze sleep stage distribution (REM/Deep/Light), sleep quality score, chronotype quiz, and caffeine cutoff time. - [AQI (Air Quality Index) Calculator](https://whichcalc.com/aqi-calculator): Convert PM2.5/PM10 to EPA AQI, health categories & recommendations, mask guidance, and air purifier sizing (CADR). - [Intermittent Fasting (IF) Calculator](https://whichcalc.com/intermittent-fasting-calculator): Calculate eating & fasting windows for 16:8, 18:6, 20:4, OMAD protocols. Track metabolic states, autophagy timing, and weight loss estimates. - [Metabolic Syndrome Calculator](https://whichcalc.com/metabolic-syndrome-calculator): Check metabolic syndrome criteria (NCEP ATP III), severity score, diabetes/heart disease risk, and personalized intervention targets. - [Biological Age Calculator](https://whichcalc.com/biological-age-calculator): Estimate biological age vs chronological based on lifestyle factors, identify aging contributors, and longevity intervention recommendations. - [HRV (Heart Rate Variability) Calculator](https://whichcalc.com/hrv-calculator): Interpret HRV score (RMSSD), 7-day tracking, recovery score combining sleep & RHR, and evidence-based tips to improve HRV. - [Child Nutritional Status Calculator (WHO Z-Score)](https://whichcalc.com/child-nutritional-status-calculator): Check child nutrition status using WHO 2006 standards: weight-for-age, height-for-age, weight-for-height, and BMI-for-age with Z-scores. - [Walking & Daily Steps Calculator](https://whichcalc.com/walking-calculator): Calculate calories from steps, walking distance and duration, Japanese 3-3-3 interval walking method, and daily step goals. - [Sleep Cycle Calculator](https://whichcalc.com/sleep-cycle-calculator): Find the optimal time to sleep based on 90-minute sleep cycles, track sleep debt, and get power nap recommendations for peak productivity. - [Medication Dosage Calculator](https://whichcalc.com/medication-dosage-calculator): Calculate medication dosage by weight and BSA, IV drip rate calculator, and medical dose unit conversions. - [Blood Sugar Calculator](https://whichcalc.com/blood-sugar-calculator): Check blood sugar levels (fasting, 2h postprandial, HbA1c), convert mg/dL to mmol/L, set HbA1c targets, and view WHO/ADA references. - [Blood Pressure Calculator](https://whichcalc.com/blood-pressure-calculator): Check blood pressure category (normal, prehypertension, hypertension), calculate MAP, track history, and view AHA guidelines. - [Ovulation & Fertility Window Calculator](https://whichcalc.com/ovulation-calculator): Predict your ovulation date, fertile window, and 3-month cycle calendar based on your last menstrual period and cycle length. - [Pregnancy Ultrasound (USG) Calculator](https://whichcalc.com/ultrasound-pregnancy-calculator): Estimate gestational age and fetal weight from ultrasound measurements (CRL, BPD, FL, HC, AC) using the Hadlock formula. - [Ideal Body Weight Calculator](https://whichcalc.com/ideal-weight-calculator): Calculate your ideal body weight using four formulas (Broca, Devine, Robinson, Miller). Compare with your current weight. - [Pregnancy BMI & Weight Gain Calculator](https://whichcalc.com/pregnancy-weight-gain-calculator): Calculate pre-pregnancy BMI and monitor pregnancy weight gain according to IOM 2009 guidelines. - [eGFR Calculator (Kidney Function)](https://whichcalc.com/egfr-calculator): Calculate estimated Glomerular Filtration Rate (eGFR) using the CKD-EPI 2021 formula. Includes chronic kidney disease staging. - [Baby Weight Calculator (WHO Standards)](https://whichcalc.com/baby-weight-calculator): Check baby weight for ages 0-24 months against WHO growth standards. Detect underweight, normal, or overweight status. - [Daily Protein Intake Calculator](https://whichcalc.com/protein-intake-calculator): Calculate your daily protein requirements based on body weight, activity level, and goals. Includes protein source recommendations. - [Body Fat Percentage Calculator](https://whichcalc.com/body-fat-calculator): Calculate your body fat percentage using the U.S. Navy method. Categories range from essential fat to obesity. - [Menstrual Cycle Tracker & Period Predictor](https://whichcalc.com/period-calculator): Track your menstrual cycle, predict next period dates, fertile window, ovulation, and cycle phases. Includes a visual calendar and cycle health assessment. - [Child Stunting Risk Calculator](https://whichcalc.com/child-stunting-calculator): Assess the risk of child stunting based on height, age, and sex according to WHO growth standards. - [Genetic Height Potential Calculator](https://whichcalc.com/child-height-predictor): Predict a child's adult height based on parental heights using the mid-parental height formula. - [Mental Health Self-Assessment Calculator](https://whichcalc.com/mental-health-test): Assess your mental well-being using standardized questionnaires to gain insight into your psychological health. - [BMI Calculator for Children & Teens](https://whichcalc.com/child-bmi-calculator): Calculate BMI specifically for children and teenagers aged 2-18 based on WHO growth standards. - [Fertility Window & Baby Gender Prediction Calculator](https://whichcalc.com/fertility-calculator): Calculate your fertile window based on your menstrual cycle and predict baby gender using the Shettles method. ## Math & Statistics Calculators Hub: [Math & Statistics Calculators](https://whichcalc.com/math-calculators) - [Standard Deviation Calculator](https://whichcalc.com/standard-deviation-calculator): Calculate mean, median, variance, standard deviation, quartiles, and IQR for any dataset, sample or population. - [Factoring Calculator (Polynomial & Number)](https://whichcalc.com/factoring-calculator): Prime factorization, divisors, GCD/LCM, and quadratic factoring with discriminant and roots. - [Percentage Change Calculator](https://whichcalc.com/percentage-change-calculator): Compute % change, % increase, % decrease, and % difference between two values - with the formula plugged in. - [Square Root Calculator](https://whichcalc.com/square-root-calculator): Compute square roots, cube roots, and nth roots with principal value, simplified radical form, and imaginary handling. - [Triangle Calculator (SSS, SAS, ASA, AAS, SSA)](https://whichcalc.com/triangle-calculator): Solve any triangle from any three elements. Law of Sines, Law of Cosines, and the ambiguous SSA case. - [Significant Figures Calculator](https://whichcalc.com/sig-fig-calculator): Count significant figures, round to N sig figs, and perform arithmetic preserving correct sig figs for chemistry, physics, and engineering. - [Fraction Calculator (Add, Subtract, Multiply, Divide)](https://whichcalc.com/fraction-calculator): Add, subtract, multiply, and divide fractions and mixed numbers with full simplification. Results as simplified fraction, mixed number, and decimal. - [Derivative Calculator (Symbolic)](https://whichcalc.com/derivative-calculator): Symbolic derivative of any polynomial, trig, exponential, or logarithmic expression. Optional numerical evaluation at a point. - [AI vs Human Employee Cost Calculator](https://whichcalc.com/ai-replace-employee-calculator): When does an AI agent break even versus a human doing the same task? Compute hourly equivalent of LLM tokens, infrastructure, and oversight against fully-loaded employee cost (salary + benefits + overhead). - [AI API Cost Calculator (LLM Tokens)](https://whichcalc.com/ai-api-cost-calculator): Estimate monthly OpenAI, Anthropic, Google Gemini, and Llama API spend from prompt tokens, completion tokens, requests per day, and model selection. - [Ideal Gas Law Calculator (PV=nRT)](https://whichcalc.com/ideal-gas-law-calculator): Solve PV = nRT for any unknown (pressure, volume, moles, temperature). Multiple unit systems supported. - [Molarity Calculator](https://whichcalc.com/molarity-calculator): Molarity = moles / liters. Solve for moles, mass (with molar mass), volume, or concentration. Includes dilution formula (M₁V₁ = M₂V₂). - [Voltage Divider Calculator](https://whichcalc.com/voltage-divider-calculator): Vout = Vin × R2 / (R1 + R2). Solve for any unknown. Includes loading-effect calculation when output drives a load. - [Ohm's Law Calculator](https://whichcalc.com/ohms-law-calculator): V = I × R. Solve for any of voltage, current, or resistance given the other two. Plus power (P = VI) calculation. - [Exponential Decay Calculator](https://whichcalc.com/exponential-decay-calculator): N(t) = N₀ × e^(−λt). Models radioactive decay, drug elimination (half-life), capacitor discharge, cooling. - [Exponential Growth Calculator](https://whichcalc.com/exponential-growth-calculator): P(t) = P₀ × e^(rt). Models population growth, compound interest, viral spread, bacterial growth. Includes doubling time and Rule of 70. - [Logarithm Calculator (log, ln, log₂, custom base)](https://whichcalc.com/logarithm-table-calculator): Compute logarithms in base 10, e (natural), 2, or any custom base. Plus antilog and the change-of-base formula. - [Factorial Calculator](https://whichcalc.com/factorial-calculator): Compute n! for any non-negative integer up to 170. Uses BigInt for arbitrary precision; supports double factorial and Stirling approximation. - [P-Value Calculator](https://whichcalc.com/p-value-calculator): Convert test statistic (z, t, χ², F) to a one- or two-tailed p-value. Reverse direction supported (p-value to critical value). - [T-Test Calculator (One & Two Sample)](https://whichcalc.com/t-test-calculator): One-sample, two-sample (independent), and paired t-tests. Returns t-statistic, df, and two-tailed p-value. - [Chi-Square Calculator](https://whichcalc.com/chi-square-calculator): Compute Pearson χ² statistic for goodness-of-fit or contingency table independence. Includes degrees of freedom and p-value. - [Linear Regression Calculator](https://whichcalc.com/linear-regression-calculator): Compute least-squares regression line (y = mx + b), R², and standard error of the estimate for paired (x, y) data. - [Pearson Correlation Calculator](https://whichcalc.com/correlation-calculator): Compute Pearson r and r² between two variables. Includes interpretation (none, weak, moderate, strong) and significance test (degrees of freedom). - [Variance Calculator](https://whichcalc.com/variance-calculator): Sample and population variance for any dataset. σ² = Σ(x − μ)² / n (population) or n−1 (sample, Bessel correction). - [Mean, Median, Mode & Range Calculator](https://whichcalc.com/mean-median-mode-calculator): All four measures of central tendency and spread for any dataset. Plus quartiles, IQR, and outlier detection (1.5 × IQR rule). - [Cylinder, Sphere & Cone Volume Calculator](https://whichcalc.com/cylinder-volume-calculator): Compute volume and surface area for cylinders, spheres, hemispheres, and cones. Converts volume to gallons (US) and liters. - [Prime Factorization Calculator](https://whichcalc.com/prime-factorization-calculator): Break any integer into its prime factors using trial division. Shows factor list, exponent form, and primality check. - [GCD & LCM Calculator](https://whichcalc.com/gcd-lcm-calculator): Find the Greatest Common Divisor (GCD/GCF/HCF) and Least Common Multiple (LCM) of 2 or more integers via Euclidean algorithm. - [Confidence Interval Calculator](https://whichcalc.com/confidence-interval-calculator): Compute confidence intervals for a population mean or proportion at 80-99.9% confidence using the z-distribution. - [Z-Score Calculator (Standard Score & Percentile)](https://whichcalc.com/z-score-calculator): Compute z-score, percentile rank, and one/two-tailed p-values under the standard normal distribution. z = (x − μ) / σ. - [Slope Calculator (Two-Point Formula)](https://whichcalc.com/slope-calculator): Find slope (m), y-intercept (b), line equation, distance, and angle between two points using m = (y₂ − y₁) / (x₂ − x₁). - [IPv4 Subnet Calculator](https://whichcalc.com/subnet-calculator): Calculate IPv4 subnet network, broadcast, usable hosts, wildcard mask, and divide a subnet into smaller blocks. - [Random Number Generator](https://whichcalc.com/random-number-generator): Generate random integers, decimals, coin flips, dice rolls, or shuffle a list using cryptographic randomness. - [Electrical Calculator (Watt, Capacitor, 3-Phase)](https://whichcalc.com/electrical-calculator): Calculate Watt-Volt-Ampere, capacitor (reactance/time constant), kWh consumption, and 3-phase power for industrial use. - [Integer Arithmetic Calculator (Negative Numbers)](https://whichcalc.com/integer-calculator): Addition, subtraction, multiplication, division of positive & negative integers with sign rules and number line visualization. - [2D Shape Area Calculator](https://whichcalc.com/2d-shape-area-calculator): Calculate area and perimeter of various 2D shapes: square, triangle, circle, trapezoid, rhombus, and regular polygons. - [Pythagorean Theorem & Triangle Calculator](https://whichcalc.com/pythagorean-theorem-calculator): Calculate triangle sides using the Pythagorean theorem, determine triangle type, compute area & perimeter, and visualize with SVG. - [Sequences & Series Calculator](https://whichcalc.com/sequence-series-calculator): Calculate the nth term and sum of n terms for arithmetic and geometric sequences, infinite series, and detect sequence patterns. - [Logarithm Calculator](https://whichcalc.com/logarithm-calculator): Calculate logarithms of any base, anti-logarithms, logarithmic equations, and verify logarithmic properties. - [Function Graphing Calculator](https://whichcalc.com/graphing-calculator): Plot mathematical functions (polynomial, trigonometric, exponential). Graph up to 3 functions simultaneously. - [Scientific Calculator](https://whichcalc.com/scientific-calculator): Full-featured scientific calculator: trigonometry, logarithms, powers, roots, factorials, and memory. Supports DEG/RAD modes. - [Function Limit Calculator](https://whichcalc.com/limit-calculator): Calculate function limits numerically. Includes a table of 12 basic limits, indeterminate forms, and L'Hopital's rule. - [Basic Physics Calculator](https://whichcalc.com/physics-calculator): Calculate velocity, force, kinetic energy, potential energy, and Ohm's law. Five fundamental physics formulas. - [Molar Mass & Mole Conversion Calculator](https://whichcalc.com/molar-mass-calculator): Calculate molar mass from chemical formulas and convert between grams, moles, and particle counts. - [Absolute Value Calculator](https://whichcalc.com/absolute-value-calculator): Calculate absolute values, solve equations |ax+b|=c and inequalities |ax+b|40 hr/wk at 1.5x). - [Military Time Converter](https://whichcalc.com/military-time-converter): Convert 12-hour AM/PM to 24-hour military time and back. Bulk-convert a timetable. - [Countdown to Date Calculator](https://whichcalc.com/countdown-to-date-calculator): Count down days, hours, minutes to any future date (birthday, wedding, retirement, deadline). - [Age in Days Calculator](https://whichcalc.com/age-in-days-calculator): Find your age in days, weeks, hours, minutes, seconds — plus next milestone days (10000, 25000 days). - [HVAC Tonnage Calculator](https://whichcalc.com/hvac-tonnage-calculator): Size central AC/heat pump in tons (1 ton = 12,000 BTU/hr). Uses Manual J shortcut: ~600 sq ft per ton with insulation/climate adjustment. - [Roof Area Calculator](https://whichcalc.com/roof-area-calculator): Calculate roof area from house footprint and pitch (rise/run). Includes hip and gable adjustments. Used for roofing material estimates. - [Stair Calculator (Rise & Run)](https://whichcalc.com/stair-calculator): Calculate stair rise, run, and stringer length from floor-to-floor height. IRC code limits: max 7¾" rise, min 10" run. - [Deck Cost Calculator](https://whichcalc.com/deck-cost-calculator): Estimate deck material + labor cost by square footage and material type (pressure-treated, cedar, composite, hardwood, IPE). - [Fence Cost Calculator](https://whichcalc.com/fence-cost-calculator): Estimate fence material + labor cost by linear foot, type (wood, vinyl, chain link, wrought iron), and gate count. - [Siding Calculator (Square Footage)](https://whichcalc.com/siding-calculator): Calculate exterior siding square footage. Subtracts windows and doors; adds 10% waste; estimates squares of vinyl siding (100 sq ft each). - [Roof Shingles Calculator](https://whichcalc.com/shingles-calculator): Calculate bundles of asphalt shingles needed (3 bundles = 100 sq ft = 1 square). Includes ridge, starter, and 10% waste. - [Drywall Calculator](https://whichcalc.com/drywall-calculator): Calculate drywall sheets needed for walls and ceiling. Includes screws, joint compound (mud), and tape. - [Concrete Block Calculator](https://whichcalc.com/concrete-block-calculator): Calculate CMU blocks needed for a wall. Standard 8×8×16 block covers 0.89 sq ft. Includes mortar and rebar quantity. - [Brick Calculator](https://whichcalc.com/brick-calculator): Calculate bricks needed for a wall. Modular brick (US standard): 6.85 bricks/sq ft. Includes mortar volume and waste factor. - [Topsoil Calculator](https://whichcalc.com/topsoil-calculator): Calculate topsoil needed in cubic yards from length × width × depth. Includes bag count (1 cubic yard ≈ 27 cubic feet ≈ 36 bags). - [Sod Calculator](https://whichcalc.com/sod-calculator): Calculate sod needed in square feet, pallets (typically 450 sq ft), or rolls. Includes installation cost estimate. - [Crown Molding Calculator](https://whichcalc.com/crown-molding-calculator): Calculate linear feet of crown molding for a room. Accounts for outside vs inside corners (waste factor) and recommended stock lengths. - [Baseboard Calculator](https://whichcalc.com/baseboard-calculator): Calculate linear feet of baseboard needed for a room. Accounts for door openings and adds 10% waste factor for cuts and corners. - [Carpet Calculator (Square Yards)](https://whichcalc.com/carpet-calculator): Calculate carpet needed in square yards (US industry standard). Includes waste factor, seam allowance for irregular rooms, and pad/installation cost. - [Lease Buyout Calculator](https://whichcalc.com/lease-buyout-calculator): Should you buy out your lease? Compare residual value to current market value (KBB, Carvana). Strong buyout if market > residual + fees. - [Car Loan Payoff Calculator](https://whichcalc.com/car-loan-payoff-calculator): See how extra principal payments shorten a car loan. Shows months saved and interest saved with different extra-payment scenarios. - [Trade-In Value Calculator](https://whichcalc.com/trade-in-value-calculator): Estimate trade-in value vs private sale. Dealers typically pay 80-90% of trade-in book value (KBB, Edmunds), which is 15-25% below retail. - [Car Depreciation Calculator](https://whichcalc.com/car-depreciation-calculator): Project car value loss over time. Typical curve: 20% year 1, 15%/yr years 2-5, then leveling. Luxury and EVs depreciate faster. - [Road Trip Cost Calculator](https://whichcalc.com/road-trip-calculator): Estimate total road trip cost: gas (MPG × distance × price), tolls, hotel, food, attractions. Splits between passengers and per-day budget. - [EV Range Calculator](https://whichcalc.com/ev-range-calculator): Estimate real-world EV range from battery kWh and efficiency (mi/kWh or kWh/100mi). Accounts for cold weather, highway speed, and HVAC drain. - [MPG Calculator](https://whichcalc.com/mpg-calculator): Calculate miles per gallon from miles driven and fuel used. Compute trip cost, US gallon vs UK gallon conversion, and L/100km equivalent. - [Car Lease Calculator](https://whichcalc.com/car-lease-calculator): Calculate monthly car lease payment from cap cost, residual, money factor, and term. Includes total of payments vs financing comparison. - [Business Days Calculator (US Federal Holidays)](https://whichcalc.com/business-days-calculator): Count working days (Mon-Fri) between two dates, optionally excluding the 11 US federal holidays. For SLA deadlines, contracts, and project planning. - [Flooring Calculator (Hardwood, Laminate, LVP)](https://whichcalc.com/flooring-calculator): Calculate square footage and boxes of hardwood, laminate, vinyl plank, or engineered flooring. Adds waste factor automatically by layout type. - [Wallpaper Calculator (Rolls & Cost)](https://whichcalc.com/wallpaper-calculator): Estimate the number of wallpaper rolls and total cost for a room. Accounts for pattern repeat, doors, windows. Standard US double roll = 33 ft × 20.5 in. - [Recipe Cost & Portion Calculator](https://whichcalc.com/recipe-cost-calculator): Calculate cost per recipe portion, profit margin for sellers, bulk purchase comparison, and menu engineering matrix. - [Solar Battery Storage Calculator](https://whichcalc.com/solar-battery-calculator): Size battery storage for off-grid/backup solar systems, discharge runtime, and ROI vs diesel generator. - [BBQ & Catering Portion Calculator](https://whichcalc.com/bbq-catering-calculator): Calculate food quantities per guest for BBQ, side dishes, beverages, Indonesian catering, and budget estimator. - [Reading Time & WPM Calculator](https://whichcalc.com/reading-time-calculator): Estimate reading time based on word count, test reading speed (WPM), audiobook duration, and reading goal tracker. - [Pomodoro & Deep Work Calculator](https://whichcalc.com/pomodoro-calculator): Calculate pomodoro sessions, deep work schedule (Cal Newport), 7-day productivity metrics, and 24-hour time blocking. - [International Time Zone Converter](https://whichcalc.com/time-zone-converter): Convert time between 30+ world cities, multi-zone meeting planner, real-time world clock, and jet lag travel predictions. - [Oven Temperature Converter](https://whichcalc.com/oven-temperature-converter): Convert oven temperatures between Celsius, Fahrenheit, and Gas Mark. Cooking temperature reference, recipe converter, and air fryer adaptation. - [Swimming Pool Volume Calculator](https://whichcalc.com/pool-volume-calculator): Calculate water volume for various pool shapes (rectangular, oval, round, slope), filling cost, chlorine dosage, and fill time. - [Dog & Cat Age in Human Years Calculator](https://whichcalc.com/pet-age-calculator): Convert dog and cat age to human years using AVMA formula by breed size, with life stage and lifespan estimates. - [Complete Electric Vehicle Calculator](https://whichcalc.com/electric-vehicle-calculator): Database of 30+ electric vehicles, calculate operating costs, 5-year TCO, ROI vs gas, range planner, federal tax credits, and CO₂ emissions. - [EV vs Gas Car Calculator](https://whichcalc.com/ev-vs-gas-calculator): Compare EV vs gas car operating costs: 5-year TCO, breakeven point, CO₂ emissions, and charging vs refueling convenience. - [Bandwidth & Download Time Calculator](https://whichcalc.com/bandwidth-calculator): Calculate download time, convert internet speeds (Mbps/MB/s), assess multi-user bandwidth needs, and reference speed test results. - [Data Storage Conversion Calculator](https://whichcalc.com/storage-converter): Convert data units: bit, byte, KB, MB, GB, TB, PB. Estimate storage for photos, videos, documents, and device capacity. - [Photo Size & DPI Calculator](https://whichcalc.com/photo-size-calculator): Convert standard photo sizes (2x3, 3x4, 4x6, passport), pixels to cm, DPI calculator, and aspect ratio tool. - [Building Materials Calculator](https://whichcalc.com/building-materials-calculator): Calculate the quantity of bricks, cement, sand, plaster, tiles, roofing, and concrete needed for construction and renovation projects. - [Screen Resolution & PPI Calculator](https://whichcalc.com/screen-resolution-calculator): Calculate screen PPI, megapixels, and compare resolutions from HD to 8K across various display sizes. - [Tire Size Calculator](https://whichcalc.com/tire-size-calculator): Calculate tire dimensions, compare two tire sizes, check speedometer correction, and ground clearance changes. - [PSU Calculator (PC Power Supply)](https://whichcalc.com/psu-calculator): Calculate the required PSU wattage based on your PC components (CPU, GPU, RAM, storage). Includes PSU tier recommendations. - [AC Size Calculator (BTU & Tonnage)](https://whichcalc.com/btu-calculator): Calculate the required BTU and tonnage for your air conditioner based on room size. Includes monthly electricity cost estimation. - [Engine Displacement (CC) Calculator](https://whichcalc.com/engine-displacement-calculator): Calculate engine displacement (CC) from bore, stroke, and cylinder count. Convert CC to liters and horsepower. - [Land Area & Unit Conversion Calculator](https://whichcalc.com/land-area-calculator): Calculate land area for various shapes and convert between units (m², are, hectare, acre). Includes price and property tax estimation. - [Date & Day Difference Calculator](https://whichcalc.com/date-difference-calculator): Calculate the number of days between two dates or find the date after a certain number of days. Includes business days. - [Tile & Flooring Calculator](https://whichcalc.com/tile-calculator): Calculate the number of ceramic tiles, granite, or stone needed for floors or walls, along with estimated costs. - [Life Expectancy Calculator](https://whichcalc.com/life-expectancy-calculator): Estimate your life expectancy based on your lifestyle habits. A motivational tool for living healthier and more meaningfully. - [Relationship Duration Calculator](https://whichcalc.com/relationship-duration-calculator): Calculate how long you have been in a relationship. View upcoming milestones and celebrate every moment together. ## Religion & Social Giving Calculators Hub: [Religion & Social Giving Calculators](https://whichcalc.com/religion-social-calculators) - [Tzedakah / Maaser Kesafim Calculator](https://whichcalc.com/tzedakah-calculator): Calculate Jewish maaser kesafim — 10% of net income for tzedakah — with tax and business-expense deductions plus a chomesh (20%) option. - [Bar / Bat Mitzvah Date Calculator](https://whichcalc.com/bar-bat-mitzvah-calculator): Find the Hebrew birthday and Bar Mitzvah (age 13) or Bat Mitzvah (12 Orthodox, 13 Reform) ceremony date including the traditional Shabbat ceremony day. - [Hebrew Date Converter](https://whichcalc.com/hebrew-date-converter): Convert between Gregorian and Hebrew (Jewish) calendar dates with major Jewish holiday tags. - [Easter Date Calculator](https://whichcalc.com/easter-date-calculator): Find Western (Catholic / Protestant) and Eastern Orthodox Easter dates for any year, plus Ash Wednesday, Palm Sunday, Good Friday, and Pentecost. - [Tithe Calculator](https://whichcalc.com/tithe-calculator): Calculate Christian tithe (10% of income) with weekly, monthly, and annual breakdowns plus lifetime giving projection. - [Zakat Maal Calculator](https://whichcalc.com/zakat-calculator): Calculate your zakat obligation on wealth (maal) based on current nisab thresholds. Supports zakat on income, savings, trade assets, and gold. ## Marketing Calculators Hub: [Marketing Calculators](https://whichcalc.com/marketing-calculators) - [Password Generator](https://whichcalc.com/password-generator): Generate cryptographically strong passwords, memorable passphrases, or PINs with live entropy and crack-time estimates. - [CPM Calculator (CPM, CPC, CPA, CTR)](https://whichcalc.com/cpm-calculator): Convert between CPM, CPC, CPA, total spend, impressions, clicks, and conversions for any ad campaign. Includes 2026 platform benchmarks. - [Token Cost Per Task Calculator (Agentic)](https://whichcalc.com/token-cost-per-task-calculator): Agentic workflows iterate 5-20× — context grows each step. Compute cost per task from input/output token mix, iteration count, and model price tier (Sonnet, Opus, GPT, Gemini). Includes prompt caching savings. - [AI Agent ROI Calculator](https://whichcalc.com/ai-agent-roi-calculator): Compute payback period and 3-year ROI for an AI agent deployment. Inputs: build cost, monthly token + infra spend, hours saved per task, loaded labor rate, error-correction overhead. - [TikTok Calculator (Engagement & Earnings)](https://whichcalc.com/tiktok-money-calculator): Calculate engagement rate, estimate TikTok earnings from Creator Fund and brand deals, and compare two accounts. - [Meta Description Length Checker](https://whichcalc.com/meta-description-checker): Check and optimize your meta description length for SEO. Ensure your meta descriptions meet Google standards. ## Exam & Grade Calculators Hub: [Exam & Grade Calculators](https://whichcalc.com/exam-calculators) - [Final Grade Calculator](https://whichcalc.com/final-grade-calculator): Find exactly what score you need on the final exam to hit your target letter grade for the class. Breakpoints for A, A-, B, C, and D shown side by side. - [GPA Calculator](https://whichcalc.com/gpa-calculator): Calculate cumulative, weighted, and target GPA on the US 4.0 scale with letter or percentage grades. - [ACT Superscore Calculator (2026 Format)](https://whichcalc.com/act-superscore-calculator): Sept 2025 ACT redesign made science optional. Superscore = average of best subject scores across attempts (English, Math, Reading, plus optionally Science). Computes 4-subject vs 3-subject composite. - [Digital SAT Score Calculator (Adaptive)](https://whichcalc.com/digital-sat-score-calculator): The digital SAT uses adaptive Module 2 — your performance on Module 1 routes you to easy or hard Module 2 questions, which set your scoring band. Estimate scaled section scores from raw correct counts. ## About - [About WhichCalc](https://whichcalc.com/about): Mission, methodology, and editorial standards for the calculator catalog. - [All Calculators](https://whichcalc.com/catalog): Full browsable index of every calculator with category filtering and sort. - [Privacy Policy](https://whichcalc.com/privacy-policy): Data handling on whichcalc.com. ## Optional - The calculator catalog updates regularly with new tools based on US Google search trends. - All calculations run client-side - inputs and results are never transmitted to a server.