Results are estimates, not financial or tax advice. Tax rates change; check the rate that applies to you with your tax office.
25% off means you pay 75% of the price: 40 becomes 30 (you save 10), 80 becomes 60 (you save 20) and 150 becomes 112.50 (you save 37.50). Stack an extra 10% on top and the total discount is 32.5%, not 35%.
How to use
- Pick a tab: Percentage, Discount, Margin or VAT / tax. Each also has its own page.
- In Percentage, choose the calculation (% of, What %, % change, Add / subtract, Reverse) and type two numbers. The answer updates as you type.
- In Discount, enter the price and tap a percentage. Add an extra % off or a coupon to stack discounts.
- In Margin, enter cost and selling price, or switch to Target margin or Markup to get the price you should charge.
- In VAT / tax, choose Add tax or Remove tax, enter the amount and tap a rate or type your own. Tap any result to copy it.
- Percentage change = (new − old) ÷ |old| × 100. Percentage difference compares two values to their average, so it’s the same in both directions.
- Reverse percentage divides by (1 + p/100): a price of 115 after a 15% increase was 100, not 97.75.
- Stacked discounts multiply: 20% off and then an extra 10% off is 28% off in total, not 30%.
- Margin is profit ÷ selling price; markup is profit ÷ cost. A 50% markup gives a 33.3% margin.
- Tax rates change and can differ by product and region (US sales tax adds city and county rates). The chips are common examples; check the rate that applies to you.
- Type decimals with a dot or a comma.
How a discount is calculated
Sale price = price × (1 − discount ÷ 100). 25% off 60 means you pay 75% of 60, which is 45, and save 15. A quick check in your head: 10% is the price with the decimal point moved one place, so 10% of 49.90 is 4.99.
Stacked discounts multiply rather than add. 30% off and then an extra 20% off is 1 − 0.7 × 0.8 = 44% off in total, not 50%. A fixed coupon is subtracted at the step where the store applies it, which changes the result slightly.
Reading sale signs
Up to 70% off means only some items reach 70%. Buy one, get one 50% off works out to 25% off the pair. When comparing deals, convert each to the final price per item rather than comparing the percentages.
Frequently asked questions
How do I calculate 20% off?
Multiply the price by 0.8. 20% off 75 is 75 × 0.8 = 60, a saving of 15.
How do I find the original price from the sale price?
Divide the sale price by (1 − discount). A price of 63 after 30% off was 63 ÷ 0.7 = 90.
Is 20% off plus an extra 10% the same as 30% off?
No. 20% then 10% is 0.8 × 0.9 = 0.72 of the price, which is 28% off in total.
What percent off is a price drop from 80 to 60?
Divide the saving by the original price: 20 ÷ 80 = 25% off.
Does the discount apply before or after sales tax?
Usually before: the store reduces the price, then adds tax to the reduced amount. In countries where prices include VAT, the discount applies to the shelf price.