Discount Calculator
Enter the full price and the percentage off to see the sale price and exactly what you save, with the working shown.
The calculator never sends or saves what you type.
How the sale price is worked out
A discount takes a percentage off the full price. What you pay is the rest: at 20% off you pay 80% of the full price, so multiply by 0.8. The saving is the other 20%.
A $50.00 item is 20% off.
- 100% − 20% = 80% of the full price remains
- 50 × 0.8 = $40.00 to pay
- You save 50 − 40 = $10.00
- Check: 40 ÷ 0.8 = $50.00 ✓
Going the other way — you know the sale price and the discount and want the price before it — is a division, not an addition: the original price calculator does it with the working shown.
Sale price and saving by discount
On a fixed $80.00 full price: the multiplier for each common discount, what you save and what you pay. The multiplier is the number to keep in your head — it turns any discount into one multiplication.
| Discount | Multiply by | You save | You pay |
|---|---|---|---|
| 10% off | × 0.90 | $8.00 | $72.00 |
| 15% off | × 0.85 | $12.00 | $68.00 |
| 20% off | × 0.80 | $16.00 | $64.00 |
| 25% off | × 0.75 | $20.00 | $60.00 |
| 30% off | × 0.70 | $24.00 | $56.00 |
| 40% off | × 0.60 | $32.00 | $48.00 |
| 50% off | × 0.50 | $40.00 | $40.00 |
| 70% off | × 0.30 | $56.00 | $24.00 |
Stacked discounts: multiply, never add
"30% off, plus an extra 20% off at the register" is not 50% off. The second discount comes off the already-reduced price, so the two multiply: 0.7 × 0.8 = 0.56. You pay 56% of the full price, a total discount of 44%. On $129.99 that is $72.79, not the $65.00 that "50% off" would suggest.
Order does not matter for percentages — 20% then 30% is the same 0.56 — but it does for a fixed-dollar coupon. A "$10 off" coupon applied before a 30% discount is worth $10 × 0.7 = $7 to you; applied after, the full $10. Most shops take the percentage off first and the dollar coupon last, which is the better order for you: the coupon keeps its full $10.
Percent off or dollars off?
Convert one into the other before comparing. "$15 off" on a $60 item is 25% off; "20% off" the same item is $12. The percentage offer looks bigger and is worth $3 less. On cheap items a dollar coupon usually wins; on expensive ones the percentage does — the crossover is where the dollar amount equals the percentage of the price.
Tax comes after the discount
Sales tax is charged on what you pay, so the discount is applied first. $129.99 at 30% off is $90.99; with 8.25% sales tax the total at the register is 90.99 × 1.0825 = $98.50. Taxing the full price and then discounting would give $98.50 too — the two multiplications commute — but a receipt that shows tax on $129.99 alongside a $39.00 discount is charging you tax on money you did not spend. Have the sale price and want the pre-tax figure back out of a total? The reverse sales tax calculator does that.
Percent off calculator: what you pay at any percent off
X% off means you pay the rest: (100 − X)% of the price. Multiply by that as a decimal — 30% off is × 0.7 — and the saving is the price minus what you pay. The calculator above works as a percent off calculator: the price goes in Full price, the percent off in Discount.
| Price and discount | Multiply by | You save | You pay |
|---|---|---|---|
| 15% off $24.99 | × 0.85 | $3.75 | $21.24 |
| 25% off $49.99 | × 0.75 | $12.50 | $37.49 |
| 30% off $79.99 | × 0.70 | $24.00 | $55.99 |
| 40% off $59.99 | × 0.60 | $24.00 | $35.99 |
| 70% off $45.00 | × 0.30 | $31.50 | $13.50 |
Open an example in the calculator above to see its check line; Show steps there has the working.
Two discounts at once
They multiply, they do not add: 30% off $79.99 is $55.99, and an extra 20% off $55.99 is $44.79. That is 44% off $79.99 in one go ($44.79, saving $35.20), not 50% off. Why it works that way: stacked discounts.
Percent off is not the percent you pay
70% off means you pay 30%: $45.00 becomes $13.50, not $31.50. A sign that says “pay 70%” is 30% off.
⅓ off is not 33% off
½ off is 50%, ¼ off is 25%, and ⅓ off is 33.33…%. ⅓ off $120 is exactly $80.00; 33% off is $80.40. For ⅓ off in the calculator, enter 33.333333 — it shows $80.00.
Buy one, get one half off is 25% off
Two items at the same price for 1.5 times the price: you pay 75%, so it is 25% off each. “Buy 3 for 2” is 33.33% off each. When the prices differ, the discounted item is usually the cheaper one, so you save less than that.
Rounding to the cent
15% off $24.99 is $21.2415, so you pay $21.24 and save $3.75 — the two still add up to $24.99. A till may round each item or the whole basket: three $2.49 items at 15% off are 3 × $2.12 = $6.36 item by item, but $6.35 on the $7.47 basket.
Quick fractions for common discounts
Some discounts are simple fractions of the price: 50% off is half, 25% off is a quarter, 20% off is a fifth, and 75% off leaves a quarter to pay. So 25% off $49.99 is about $12.50 off, and the calculator gives $37.49 to pay, rounded to the cent.
Frequently asked questions
How do you calculate a discount?
Multiply the full price by the percentage off, as a decimal, to get the saving; subtract that from the full price to get the sale price. $50 at 20% off: 50 × 0.20 = $10 saved, so you pay $40. In one step, multiply the full price by (1 − 0.20) = 0.8.
How do I calculate 20% off a price?
Move the decimal point one place left for 10%, double it for 20%, and take that off. $129.99 → 10% is $13.00, 20% is $26.00, so you pay $103.99. Or multiply by 0.8 directly: 129.99 × 0.8 = $103.99.
What is 25% off $80?
You save $20 and pay $60. A quarter of 80 is 20, and 80 − 20 = 60. The multiplier for 25% off is 0.75: 80 × 0.75 = 60.
Do two discounts add up?
No — they multiply, and the total is always less than the sum. 25% off then an extra 10% off is 0.75 × 0.9 = 0.675 of the full price, a 32.5% discount, not 35%. The second discount is taken from an already-reduced price, so it is worth less in dollars than the same percentage off the full price.
How do I work out the discount percentage from two prices?
Full price minus sale price, divided by the full price, times 100. A $129.99 item selling for $90.99 is (129.99 − 90.99) ÷ 129.99 × 100 = 30% off. Divide by the full price, not the sale price — dividing by 90.99 would say 42.9%, which is the markup back up, a different number.
Is sales tax charged on the sale price or the full price?
On the sale price — the price you actually pay. $129.99 at 30% off is $90.99; at 8.25% tax the total is 90.99 × 1.0825 = $98.50. A mail-in rebate is the exception: tax is charged on the price before the rebate, because the shop still sells the item at that price.
How do I find the price before the discount?
Divide the sale price by 1 minus the discount as a decimal — do not add the percentage back. $60 after 25% off was 60 ÷ 0.75 = $80; adding 25% to $60 gives $75, which is wrong. The original price calculator on this site does that division and shows the working.
What is 30% off plus an extra 20% off?
44% off, not 50%: you pay 70% of the price, then 80% of that, and 0.7 × 0.8 = 0.56. On $79.99 that is $55.99 after the 30%, then $44.79 after the extra 20% — the same $44.79 as 44% off in one go, a saving of $35.20.
Is 70% off the same as paying 70% of the price?
No. At 70% off you pay the other 30%: $45.00 becomes $13.50 and you save $31.50. Paying 70% of the price is a 30% discount.
Is buy one, get one 50% off the same as 50% off?
No. Two items at $20 cost $30.00 instead of $40.00, which is 25% off each. Only buy one, get one free is 50% off each — and when the two prices differ, the half-price item is usually the cheaper one, so you save less.
What does “up to 70% off” mean?
That 70% is the biggest discount in the sale, not the discount on everything. A $50 item could be $15.00 at 70% off or $40.00 at 20% off in the same sale; check the label on the item you want.