What this tool does and when to use it
Sale price = price × (1 − percent off ÷ 100). 25% off means you pay 75%, so $80 × 0.75 = $60. Two discounts multiply, they do not add: 30% off and then an extra 20% off is 44% off in total, not 50%.
How to calculate percent off a price
- Turn the discount into what you pay. 25% off means you pay 75%, or 0.75.
- Multiply. Price × 0.75 is the sale price. Price minus the sale price is your saving.
- Stack extras one at a time. For an extra discount, multiply the sale price again, then add sales tax last.
How to calculate percent off
Take the discount away from 100 to find what you pay, then multiply. 25% off means you pay 75%, so $80 × 0.75 = $60. Your saving is the price minus the sale price, $20, which is also $80 × 0.25.
A fast mental check: 10% of a price is the price with the decimal point moved one place left. 10% of $80 is $8, so 20% is $16 and 30% is $24.
Percent off chart
Sale prices for common prices and discounts:
| Price | 10% off | 20% off | 25% off | 30% off | 40% off | 50% off |
|---|---|---|---|---|---|---|
| $20 | $18 | $16 | $15 | $14 | $12 | $10 |
| $50 | $45 | $40 | $37.50 | $35 | $30 | $25 |
| $80 | $72 | $64 | $60 | $56 | $48 | $40 |
| $100 | $90 | $80 | $75 | $70 | $60 | $50 |
| $150 | $135 | $120 | $112.50 | $105 | $90 | $75 |
| $250 | $225 | $200 | $187.50 | $175 | $150 | $125 |
Extra percent off: why discounts do not add up
When a shop says "an extra 20% off sale prices", the second discount comes off the already reduced price. 30% off and then 20% off is 0.7 × 0.8 = 0.56 of the price, so you pay 56% and the total discount is 44%, not 50%. On a $100 jacket that is $56, not $50. Put both discounts in the calculator above to see the real total.
Percent off with sales tax
In the US, sales tax is added at the till on the price after discounts. $80 with 25% off is $60, and with 8% sales tax you pay $60 × 1.08 = $64.80. In the UK and most of Europe, shelf prices already include VAT, so the percent off is the whole story.
Is it a real deal?
- Check the starting price. A percent off is only as good as the price it is taken from. Compare the sale price with what the item sold for a month ago.
- Compare deals with the same maths. "Buy one, get one 50% off" on two equal items is 25% off each. "Buy two, get one free" is 33.33% off each.
- Watch the threshold offers. "$20 off when you spend $100" is 20% off only if you spend exactly $100.
Know the sale price and want the original? Use the reverse percentage calculator.
Percent off in Excel and Google Sheets
- Sale price:
=A1*(1-B1)with B1 typed as 25%. - Saving:
=A1*B1. - Two discounts:
=A1*(1-B1)*(1-C1).
