Discount Calculator
Find a sale price, work backward to the original price, or calculate the percentage saved. Add a second discount and estimate your total with tax.
Your result
How to calculate a discount
For a percentage discount, multiply the original price by the discount percentage divided by 100. Subtract that saving from the original price. For example, 20% off 100 saves 20 and gives a sale price of 80 before tax.
A fixed discount subtracts a currency amount instead. This calculator treats that amount as a discount on each item, not as one coupon for the whole order.
Stacked discounts are applied in sequence
A 20% discount followed by another 10% discount changes 100 to 80, then to 72. The combined discount is 28%, not 30%. The second percentage applies to the reduced price.
Find the original price
With a percentage discount, original price = sale price ÷ (1 − discount ÷ 100). For a fixed discount, add the discount amount back to the sale price. Reverse calculations here use one discount and prices before tax.
How do I find the discount percentage?
Subtract the sale price from the original price, divide the saving by the original price, then multiply by 100. An original price of zero cannot produce a meaningful percentage.
Why cannot I reverse a 100% discount?
A 100% discount makes every original price zero after discount. The original price cannot be uniquely recovered from that information.
How are tax and rounding handled?
Tax is calculated on the discounted subtotal for all items. Calculations retain precision internally and displayed amounts use the selected currency’s standard decimal places. A store that rounds each item or discount separately may produce a slightly different total. Prices entered should exclude tax.
Does this include shipping or coupon restrictions?
No. Shipping, minimum-spend rules, excluded products, discount caps and store-specific coupon rules are not modeled. A fixed discount greater than the original item price is rejected.