The Discount Calculator helps you quickly and accurately calculate the final price after a discount.
Supports single discounts as well as stacked (double) discounts commonly used by marketplaces and retail stores. This calculator can also add tax so you know the actual final price you need to pay.
Calculator information
📋 How to use this calculator
- Enter the original price of the item before any discount in USD.
- Select the discount type: single percentage (e.g., 30%) or stacked discounts (e.g., 30% then another 20%).
- Enter the discount percentages. For stacked discounts the calculator applies them sequentially - it does not add them together.
- Optional: toggle sales tax (default 7%) to simulate the final out-the-door price.
- Click Calculate. You will see the post-discount price, dollars saved, and the effective discount percentage.
🧮 Single and stacked discounts
Single discount: P_final = P_original x (1 - d%)
Stacked discount: P_final = P_original x (1 - d1%) x (1 - d2%)
- P_original = price before discount
- P_final = price after discount
- d, d1, d2 = discount percentages (as decimals: 30% = 0.30)
Stacking 30% + 20% is NOT the same as 50% off. The actual result is 0.70 x 0.80 = 0.56, an effective discount of 44%, not 50%.
💡 Worked example: $80 shoes, 30% storewide + extra 20% member discount, 7% sales tax
Given:- Original price = $80.00
- First discount (storewide) = 30%
- Second discount (member) = 20%
- Sales tax = 7%
Steps:- First discount: 80.00 x (1 - 0.30) = 80.00 x 0.70 = $56.00
- Second discount: 56.00 x (1 - 0.20) = 56.00 x 0.80 = $44.80
- Effective total discount: (80.00 - 44.80) / 80.00 = 44% (not 50%!)
- Sales tax 7%: 44.80 x 1.07 = $47.94
Result: Final price after discounts plus tax = $47.94. Total saved vs. original = $32.06 (about 38% net of tax). A 30+20 stack is not 50% - the difference is 6 percentage points.
❓ Frequently asked questions
Why isn't 50% + 20% the same as 70% off?
Because the second discount is applied to the already-discounted price, not the original. 50% + 20% means: price drops to 50% of the original, then another 20% comes off that, so 50% x 80% = 40% of original, an effective discount of 60%, not 70%. Always apply discounts sequentially - never just add them.
What's the difference between 'Up to 70% off' and '70% off'?
'Up to 70%' means a MAXIMUM of 70% - only select items hit that ceiling. Most items typically get a much smaller discount. Always compare the actual before-and-after price to verify.
How do I figure out the original price when I only know the discounted price?
Use the reverse formula: P_original = P_final / (1 - d%). Example: discounted price $600 with a 25% discount. P_original = 600 / 0.75 = $800. This is handy for spotting retailers who inflate the 'original' price before applying a 'discount.'
Is sales tax applied before or after the discount?
In every U.S. state, sales tax is calculated on the final selling price after manufacturer/store discounts and most coupons (per state Department of Revenue guidance). Order: original price -> apply discount -> add sales tax. A retailer that taxes the pre-discount price is overcharging the consumer. Manufacturer rebates can vary; check state rules for edge cases.
How do I maximize savings during big sales (Black Friday, Cyber Monday, Prime Day)?
Track prices for 1-2 weeks BEFORE the event with tools like CamelCamelCamel or Honey - many retailers raise prices first, then 'discount' them. Stack store discount + credit card cashback + portal cashback (Rakuten, TopCashback). Done right, effective savings can reach 30-50% off normal price.
📚 Sources & references
Last updated: May 11, 2026