Discount Calculator

How to use

1. 1Pick the mode: Find sale price (forward), or Reverse from sale price (back-out the original price from a discount percent).
2. 2Forward mode: enter the original price and optional quantity, then add one or more discount rows (percent off or amount off). Use the quick-percent buttons to set common rates fast.
3. 3Forward mode: stack as many discounts as you need; rows compose top to bottom the way real coupon stacking works at the register.
4. 4Forward mode: tick Add sales tax after discount and enter the combined rate to see the total with tax on the post-discount subtotal.
5. 5Reverse mode: enter the sale price you paid and the discount percent. The original price is sale divided by (1 minus the discount percent over 100).
6. 6Pick a currency for display formatting. Read the headline result and use any Copy button or Copy summary to share the breakdown.

About this tool

Discount Calculator turns the most common shopping math into a clear breakdown in your browser. Forward mode takes an original price, an optional quantity, and one or more stacked discounts and reports the sale price, total savings, the effective discount as a single percent, and an optional total with sales tax applied to the post-discount subtotal. Each discount row can be either a percent off (for example 20% off everything) or an amount off (for example a 5 USD coupon), and rows are applied top to bottom so they compose the way real coupon stacking works at the register: a 30% off promotion followed by an extra 20% off coupon does not equal 50% off, it equals 1 minus 0.7 times 0.8, which is 44%, and the step-by-step panel shows exactly how the price walks down through each row so anyone can verify the math. A quick-percent toolbar handles the most-searched values (10, 15, 20, 25, 30, 40, 50, and 70 percent off), an optional sales tax rate is applied to the post-discount subtotal (which matches how most US jurisdictions treat coupons), and the per-unit sale price is reported when quantity is greater than one so wholesale and bulk math just works. Reverse mode takes the sale price someone actually paid plus the discount percent and divides backwards to find the original price using the formula original equals sale divided by (1 minus rate over 100), which answers questions like 'I paid 80 dollars after 20% off, what was the list price' that come up on receipts, gift-card balances, and refund disputes. Money is rounded to the currency's natural minor unit (cents for USD, EUR, GBP, CAD, AUD, INR, TRY; whole units for JPY) using integer-cents rounding to avoid floating-point drift, and amounts are formatted with Intl.NumberFormat for eight currencies for display only (no FX rates, no API calls). Useful for shoppers comparing 25% off versus 20 dollars off on the same item, deal hunters checking whether stacked coupons clear a free-shipping threshold, ecommerce sellers planning markdown ladders, students and teachers solving percent-off word problems, and anyone who needs a fast no-signup answer to 'what is X percent off Y' or 'what was the original price'. Calculations run entirely in your browser, so the prices and codes you type never leave your device.

Free to use. Works in your browser. No signup, no login.