About this tool
A stacked discount calculator (coupon stack calculator) shows the final price when more than one coupon is used on the same item.
Enter the original price, then up to five coupons in the order the shop applies them, each either a percent off or a fixed amount off.
The table shows the price after every step, then the final price, the total saved and the total discount rate. Why is 10% plus 20% not 30%?
Each percent coupon takes its share of the price left after the previous coupon, so 10% then 20% on 100 gives 100 x 0.9 x 0.8 = 72, a 28% total discount. Does the order matter?
Two percent coupons give the same result in any order, but a fixed amount and a percent coupon do not: 100 with 20 off and then 10% is 72, while 10% and then 20 off is 70. How do I find the best order?
Try both orders and compare the final price. A percent coupon is worth more on a higher price, so using a fixed coupon first usually lowers the saving from a percent coupon.
A coupon never takes the price below zero here. Real shops may block stacking, set a minimum order, round amounts or exclude shipping, so treat the result as a reference calculation and check the shop's terms.
For a single percent discount use the Discount Calculator. Everything is calculated in your browser and nothing is sent anywhere.
How to use
- Enter the original price.
- Set each coupon as percent or fixed amount, in the order the shop applies them, and fill in its value.
- Read the price after each step, the final price and the total discount rate, then try another order to compare.