Compare the Snowball strategy (smallest balance first) and Avalanche strategy (highest APR first) for paying off multiple debts. See payoff dates, total interest, and how much faster an extra monthly payment makes you debt-free.
Add up to eight debts with balance, APR, and minimum payment. The simulator applies each minimum every month, computes monthly interest, then rolls the optional extra payment into the priority debt for each strategy. Outputs debt-free date, months to payoff, total interest paid, payoff order, and the dollar gap between strategies.
Disclaimer: Estimates assume monthly compounding, fixed APRs, and minimums that do not decrease as balances fall (most issuers reduce minimums over time, which extends payoff). Watch for introductory APR expiration on credit cards.
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Calculator information
📋 How to use this calculator
- Add each debt you owe: name, balance, APR, and minimum payment.
- Set an extra monthly payment - any amount above the sum of minimums that you can commit to.
- Choose strategy: Snowball (smallest balance first) for motivation, or Avalanche (highest APR first) for math optimization.
- Result shows months to debt-free, total interest, payoff order, and a side-by-side comparison of the two strategies.
- Tip: the math always favors Avalanche, but Snowball wins on psychology - pick the one you will actually stick with for 2-5 years.
🧮 Debt Payoff Simulation
Monthly: Balance += Balance x APR/12 - Min - Extra(priority)
- Each debt accrues monthly interest = Balance x (APR / 12 / 100)
- Each debt receives at minimum its declared min payment
- Extra payment goes entirely to the priority debt (smallest balance for Snowball, highest APR for Avalanche)
- When a debt hits $0, its minimum 'snowballs' onto the next priority debt
- Continue until all balances are $0 or 480 months (40 years) elapse
Real lenders reduce minimum payments as balances fall, which extends payoff time (the 'minimum payment trap'). This calculator assumes minimums stay flat - your real payoff with declining minimums will be 6-24 months longer.
💡 Worked example: Three Debts, $200/month Extra
Given:- Credit card: $6,500 @ 24.5% APR, $180 min
- Auto loan: $14,000 @ 7.5% APR, $320 min
- Student loan: $22,000 @ 6.5% APR, $210 min
- Total extra/month: $200
Steps:- Sum of mins: $180 + $320 + $210 = $710. Plus $200 extra = $910 total monthly debt payment
- Avalanche order: credit card (24.5%), auto (7.5%), student (6.5%)
- Snowball order: credit card ($6,500), auto ($14,000), student ($22,000) - same order in this case!
- Pay off credit card first: ~28 months with $200 extra, total interest ~$1,820
- After credit card paid, $180 minimum + $200 extra = $380 extra rolling to auto loan
- Pay off auto loan: ~13 more months from there, total interest ~$2,300
- After auto loan paid, $320 minimum + $380 extra = $700 extra rolling to student loan
- Pay off student loan: ~20 more months, total interest ~$1,400
- Total debt-free: 28 + 13 + 20 = 61 months (~5 years), total interest ~$5,520
Result: Debt-free in ~5 years with $5,520 total interest. Without the $200 extra, the same debts would take 7+ years and $9,000+ in interest.
❓ Frequently asked questions
Snowball or Avalanche - which is better?
Avalanche (highest APR first) is mathematically optimal - you save the most interest because you starve the most expensive debt first. For pure dollars saved, Avalanche always wins or ties. Snowball (smallest balance first) wins on psychology - killing a debt in months 1-3 delivers a dopamine hit that keeps people consistent. A 2016 Northwestern/Kellogg study found Snowball users paid off more total debt because they stayed engaged. Pick the one you will actually finish.
How much extra should I pay each month?
As much as you can without compromising your essentials. A practical floor: round up each minimum to the nearest $25 ('round-up trick'). A solid target: 10-20% of your take-home pay if you have significant high-interest debt. After credit cards are gone, redirect the freed-up cash flow to your 401(k) match, emergency fund, and then student loans / mortgage. Live below your means until balances hit $0.
Should I save an emergency fund before paying off debt?
Yes - have at least $1,000 to $2,000 cash before going hard on debt payoff. Without a buffer, the next unexpected expense (car repair, medical bill) goes on a credit card and undoes weeks of progress. The Dave Ramsey Baby Step sequence (popular but not perfect): $1,000 starter EF → pay off all non-mortgage debt → 3-6 month EF → invest. Some prefer a fuller 3-month EF first if their job is volatile.
What if I cannot make even the minimum payments?
Call your creditors before you miss a payment. Options vary by debt type: credit cards may offer a hardship program (reduced rate for 6-12 months); auto lenders may offer a payment skip or extension; student loans (federal) have income-driven repayment plans and forbearance. Non-profit credit counseling (NFCC.org) is free or low-cost and can negotiate a debt management plan. Avoid debt-settlement companies that charge fees and trash your credit.
Does paying off debt help my credit score?
Yes, especially credit card balances. Credit utilization (balance / credit limit) is about 30% of your FICO score - getting all cards under 30% utilization and ideally under 10% can boost your score 50-100 points in a few months. Paying off installment loans (auto, student, mortgage) has a smaller short-term impact but builds a longer 'paid in full' history that helps over years. Do not close paid-off credit cards immediately - older accounts help your credit age.
📚 Sources & references
Last updated: May 13, 2026