A discount is a percentage taken from an original price. To calculate it correctly, identify the original price, calculate the savings and then subtract that savings from the original amount.
One discount
For a 25% discount on 80, multiply 80 by 0.25 to get savings of 20. Subtract 20 to get a sale price of 60.
Two discounts are not added
Two 10% discounts applied one after another are not the same as one 20% discount. The second reduction is calculated from the already reduced price. Keep each step separate.
Discount, tax and delivery
Store checkout pages can add tax or delivery after the discount. A calculator can show the discounted price, but the final amount depends on the seller’s conditions.
Compare like with like
Compare final prices for the same product size, quantity and return conditions. A higher percentage discount is not always the lower final price.
Quick questions
Can a discount exceed 100%?
Not for a normal sale price. A 100% discount makes the item free before any separate charges.
Does a discount include tax?
It depends on the seller. Check whether tax is calculated before or after the discount.
Last reviewed: 5 September 2026. If you spot an error, use our feedback page.