How to work out a discount
- 1Choose what you want to find: the price after a discount, the discount percentage from two prices, or two discounts in a row.
- 2Enter the original price, then the discount percentage(s) or the sale price.
- 3Read the price you pay, the amount you save and the percentage off, with each step of the sum shown.
Discount formulas
- 01Saving = price × discount% ÷ 100; price you pay = price − saving
- 02Discount % = (original price − sale price) ÷ original price × 100
- 03Two discounts: final price = price × (1 − d₁) × (1 − d₂)
A percentage discount takes that share off the price. A 20% discount on 5,000 removes 20% of 5,000 — that is 1,000 — leaving 4,000 to pay. To do it in your head, 10% is the price with one digit dropped (500), so 20% is double that.
To find what percent off a sale is, divide the amount taken off by the original price, not by the sale price. A jacket cut from 5,000 to 3,750 is 1,250 off, and 1,250 ÷ 5,000 = 25% off.
Discounts in a row multiply rather than add: 20% off and then a further 10% off leaves 0.8 × 0.9 = 0.72 of the price, which is 28% off in total, not 30%.
Discount calculation example
A 20% discount on 5,000 saves you 1,000.
So the price you pay is 4,000.
Good to know
- To check a shop's "X% off" quickly, remember 10% is one-tenth and 50% is half.
- Two discounts don't add up: 20% then 10% off is not 30% off — it's 28% off the original.
- When a tag shows only the old and new price, use "Discount % from two prices" to see the real percentage before you compare deals.
- Compare the amount you save, not just the percentage, when deciding between deals.
Discount calculator — common questions
How do I calculate a discount?
Multiply the price by the discount percentage and divide by 100 to get the saving, then subtract it from the price. A 20% discount on 5,000 saves 1,000, so you pay 4,000.
How do I calculate the discount percentage between two prices?
Subtract the sale price from the original price, divide by the original price and multiply by 100. From 5,000 down to 3,750 is 1,250 off, and 1,250 ÷ 5,000 × 100 = 25% off.
How much is 20% off 5,000?
20% of 5,000 is 1,000, so the sale price is 4,000.
Are two stacked discounts the same as adding them?
No. 20% off and then 10% off is 0.8 × 0.9 = 0.72 of the price, which is 28% off the original — not 30%.
How do I find the original price before a discount?
Divide the sale price by (1 − discount ÷ 100). If you paid 4,000 after 20% off, the original price was 4,000 ÷ 0.8 = 5,000.
Sources
- Percentage discount — standard arithmetic
Formulas last reviewed: September 30, 2026 ·How we check our formulas