Discount calculator

What will I really pay?

A "30% off" sign is easy to understand, but working out the sale price on the spot is not, especially when there is a second discount, a coupon on top or tax to add. This calculator gives the final price and your saving as you type, and it also works backwards: if you know the sale price and the discount, it tells you the price before the discount.

How a discount works

A discount of a given percentage leaves you paying the rest. A 25% discount on 80 leaves 75% to pay, which is 80 × 0.75 = 60, so you save 20. The calculator shows the price after the discount, the amount saved and the percentage, which is useful for comparing offers expressed in different ways, such as "20 off" against "25% off".

Two discounts are not added together

A common trap is stacked discounts. Two successive discounts of 20% and 10% are not a 30% discount. The second percentage applies to the price already reduced by the first: 100 becomes 80, and 10% off 80 leaves 72, a total discount of 28%. The optional second discount field applies discounts in that order and shows the real combined percentage, which is always a little less than the sum.

Working back to the original price

If you see a sale price and want to know the original, choose the reverse mode. The sale price is divided by the share you pay, so a coat now priced at 60 after a 25% reduction was 80 before. The same works with two discounts. It is handy for checking whether a "before" price on a label is genuine.

Adding tax

Some prices are shown before tax. Enter a tax rate and the calculator adds it to the discounted price, so you see what you will pay at the till. Tax is added after the discount, which is the usual order, but a few shops apply coupons after tax, so check how your offer works.

What it does not do

It does not handle "buy one get one free", fixed amount coupons or minimum-spend conditions, which need their own arithmetic. To compare a discount with a percentage change, see the percentage calculator.