How to calculate a discount
Multiply the price by the discount percentage divided by 100 to get the amount you save. Subtract that from the price to get the sale price.
sale price = price − price × discount ÷ 100
A shortcut is to multiply the price by 1 minus the discount as a decimal. For 20% off, multiply by 0.8.
Examples
- A jacket costs 120 and is 30% off. You save 120 × 0.30 = 36, so you pay 84.
- A pair of shoes costs 80 and is 20% off. 80 × 0.8 = 64.
Two discounts in a row
Two discounts do not add together. Take 20% off 100 to get 80, then 10% off that to get 72. The total saving is 28%, not 30%, because the second discount applies to the lower price.
Find the original price
If you know the sale price and the discount, divide the sale price by 1 minus the discount as a decimal. A sale price of 64 after 20% off gives 64 ÷ 0.8 = 80.
Common questions
How do I find the discount percentage from two prices?
Use the Percent change tab with the original price as the starting number and the sale price as the new number. Going from 80 to 64 gives −20%, which is a 20% discount.
How do I work out the original price before a discount?
Divide the sale price by 1 minus the discount as a decimal. If a coat costs 75 after 25% off, the original price is 75 ÷ 0.75 = 100.
Do two discounts add up?
No. The second discount applies to the already reduced price, so 20% off followed by 10% off is a 28% saving in total.