A discount calculator finds the sale price and amount saved from an original price and discount. This tool also lets you work backward from a sale price, combine sequential discounts correctly, use fixed-amount coupons, compare two offers, and optionally estimate tax using a rate you enter. Stacked discounts are applied one after another rather than simply added.
When you stack discounts, the second discount applies to the newly reduced price, not the original price. Adding 20% + 10% does not equal a 30% discount.
Which saves more: a percentage off (e.g., 20%) or a fixed-amount coupon (e.g., $15)? It depends on the item's original price. For lower-priced items, a fixed-amount coupon often saves more. For higher-priced items, a percentage discount usually yields greater savings.
Tax treatment of coupons, rebates, and products varies by jurisdiction. This option applies the rate you enter to the post-discount amount as a simple estimate. We cannot infer or promise exact checkout taxes based purely on a simple rate.
You can use the "Compare Deals" mode in the calculator to enter two distinct offers. It compares both order total and per-item checkout cost so you can see which offer is lower on each measure.
Direct answer
A discount calculator subtracts a percentage or fixed amount from an original price to find the sale price. When discounts are stacked sequentially (e.g., 20% off plus an extra 10% off), the second discount applies to the newly reduced price, resulting in an effective discount that is lower than simply adding the percentages together.
For multiple percentage discounts, each step multiplies the current price by the fraction remaining (1 minus the discount rate). The process repeats for each step.
Final Price = Original Price × (1 − Discount 1) × (1 − Discount 2) ...
| Variable | Meaning | Unit or range |
|---|---|---|
| Original Price | Starting price before any discount | currency |
| Discount | Markdown percentage (as decimal) or fixed amount | rate/currency |
For a $100 item with 20% off and an extra 10% off, Step 1 leaves $80. Step 2 takes 10% off $80 ($8), leaving a final price of $72 (an effective 28% discount).
Sale price is the per-item price after the entered discounts and before optional tax. If you enter a tax rate, the calculator separately estimates tax and checkout/order total. The effective discount rate measures total savings against the original price.
Each discount is applied sequentially to the current running total, not the original starting price.
Divide the sale price by (1 minus the discount decimal).
This calculator adds optional tax to the final post-discount price as a simple estimate, because tax treatment varies by jurisdiction.