How do I find the final sale price?

Use sale price equals original price times one minus the discount percentage divided by 100.

Everyday maths calculator

Discount Calculator

Q: How do I calculate 20% off?

Multiply the original price by 20% to find the saving, then subtract it from the original price.

Q: Are two discounts added together?

Usually no. A second discount is applied to the already-discounted price, so the effective discount is lower than simply adding both percentages.

Work out a sale price, total saving, stacked discounts and quantity totals from the original price and discount percentage.

Use the calculator Stacked discounts

Calculate a discount

Enter the original price and discount percentage. You can also add a second discount and quantity to see the total saving across more than one item.

Original price Use the price before any discount.

Discount (%) For example, enter 20 for 20% off.

Extra discount (%) Optional. Applied after the first discount.

Quantity Use this for multiple items at the same discounted price.

Decimal places

Result

£80.00

You save £20.00 on a £100.00 item.

Sale price each£80.00

Total saving£20.00

Total to pay£80.00

Effective discount20.00%

£100.00 × 20% = £20.00 saving.

Stacked discounts: a second discount is applied to the already-discounted price, not the original price. 20% off then another 10% off gives 28% off overall, not 30%.

How the discount calculator works

The calculator multiplies the original price by the discount percentage to get the saving, then subtracts that saving from the original price.

Discount amount = Original price × Discount % ÷ 100
Sale price = Original price − Discount amount

If there is an extra discount:
Extra saving = Sale price × Extra discount % ÷ 100
Final price = Sale price − Extra saving

For money values, the result is usually rounded to 2 decimal places. Related Calculatorz pages include Grocery Cost Calculator, Tip Calculator and How to compare unit prices when shopping.

How stacked discounts work

Two discounts are applied one after the other. This means 20% off followed by 10% off is not the same as 30% off.

£100 with 20% off£100 − £20 = £80.

Then another 10% off10% of £80 is £8, so the final price is £72.

Total saving£100 − £72 = £28.

Effective discount£28 ÷ £100 = 28% overall.

Discount examples

Original price	Discount	Sale price	Saving
£100.00	20%	£80.00	£20.00
£49.99	15%	£42.49	£7.50
£250.00	35%	£162.50	£87.50

Common discount mistakes

Adding stacked discounts together: 20% then 10% is 28% overall, not 30%.
Mixing up saving and sale price: the saving is what comes off; the sale price is what you pay.
Ignoring quantity: a small saving can become meaningful when buying several items.
Comparing different pack sizes: use a unit price calculator when the quantities are not the same.