Discount calculator
Work out the final price after a discount and how much you save, even with a second stacked discount. You can also do the reverse: find the original price from the discounted one.
From price to saving: how a discount is worked out
Working out a discount means working out a percentage and subtracting it. A £80 coat with 30% off: the discount is 80 × 30 ÷ 100 = £24, and the final price is 80 − 24 = £56. The shortcut is to multiply directly by what's left: if you take off 30%, you pay 70%, so 80 × 0.70 = £56 in a single step.
Stacked discounts: the usual trap
"30% off plus an extra 20%" is not a 50% discount. Successive discounts apply one on top of the previous result, they don't add up. On £100: the first 30% leaves the price at £70, and the extra 20% is worked out on that £70, bringing it to £56. The real discount is 44%, not 50%. That's why "off the already-reduced price" offers sound better than they are; it's worth checking the final price rather than trusting the sum of the signs.
Working backwards: what was the original price?
Sometimes you see the sale price and the percentage and want to know the original. You don't add the percentage to the sale price: you divide. If something costs £56 after 30% off, the original was 56 ÷ 0.70 = £80. It's the same principle as stripping out VAT: the percentage was applied to the starting price, not to the reduced one.
When a sale and a voucher combine
If a shop applies a sale and a voucher, and both are percentages, the order doesn't change the final result (20% then 10% gives the same as the other way round). What does matter is if one of them is a fixed amount: in that case, whether it's applied before or after the percentage changes what you pay. This tool shows you the final price and the total saving so you can compare offers on equal terms.