Discount Calculator
Find the sale price and savings, including "extra % off" stacked discounts and tax.
About this discount calculator
Shopping discounts are easy to misread. "25% off plus an extra 20%" is not 45% off — the second discount applies to the already-reduced price, so the real total is 40%. This calculator applies discounts in the right order, shows how much you save, and adds sales tax to give the price you'll actually pay at checkout.
Store owners can use it the other way around to check promotional pricing before a sale goes live.
How to use the Discount Calculator
- Enter the original price.
- Enter the discount percentage and any extra percentage off.
- Add your sales tax rate if you want the checkout total.
- Read the final price and your savings.
How stacked discounts work
Sale price = Price × (1 − d1) × (1 − d2)
Each discount multiplies the remaining price, so the combined discount is 1 − (1 − d1)(1 − d2). Sales tax is then calculated on the discounted price.
Worked example
A $120 jacket at 25% off is $90. An extra 20% off brings it to $72 — a total discount of 40%, saving $48. With 8.25% sales tax the checkout price is $77.94.
Tips for better results
- Compare a percentage coupon with a fixed-dollar coupon on the actual price — on cheaper items a $10 coupon can beat 20% off.
- Check whether the extra discount applies to sale items before you shop.
Frequently asked questions
Is 20% off then 10% off the same as 30% off?
No. It equals 28% off: 0.8 × 0.9 = 0.72 of the original price.
How do I find the original price from a sale price?
Divide the sale price by (1 − discount). A $72 item that was 40% off originally cost 72 ÷ 0.6 = $120.
Last reviewed: October 2026 · Results are calculated in your browser.