Percent Off Calculator
Type a price and a percent off — the sale price and savings update instantly. For “extra 20% off already-reduced” deals, add the second discount: stores apply it to the reduced price, not the original.
Percent off means: sale price = original × (1 − discount). 20% off $80 is $64; an extra 20% off that is $51.20 — not 40% off.
- 20% off $80$64.00
- 30% off $80$56.00
- Extra 20% off the $64$51.20 (36% total)
- RuleStacked discounts multiply, they don’t add
Arithmetic shown live by the calculator below.
Common percent-off shortcuts
| Discount | Shortcut | On $80 |
|---|---|---|
| 10% off | Move the decimal: $8 off per $80 | $72.00 |
| 20% off | Double the 10% figure | $64.00 |
| 25% off | Quarter off: divide by 4 | $60.00 |
| 33% off | Roughly a third off | $53.60 |
| 50% off | Half | $40.00 |
| 70% off | Pay 30%: price × 0.3 | $24.00 |
The trap is stacked discounts: “30% off plus an extra 20% off” is 44% off total (0.7 × 0.8 = 0.56 of the price), never 50%. Retailers know shoppers add the numbers; the register multiplies them.
Frequently asked questions
How do I calculate 20 percent off?
Multiply the price by 0.80 (or find 10% by moving the decimal, then double it and subtract). 20% off $45 = $36.
Do stacked discounts add together?
No — they multiply. 30% off then an extra 20% off leaves you paying 70% × 80% = 56% of the original, a 44% total discount.
Is percent off calculated before or after tax?
Before. Discounts reduce the sticker price; sales tax then applies to the discounted amount in nearly all US states.
What's the difference between percent off and percentage discount?
Same thing, different phrasing. Both mean the price is reduced by that share of the original.
Sources & methodology
Sources: NumberBench methodology.
Results update as you type and are general estimates, not financial advice.