How to use the discount calculator
- Choose what you want to find: the sale price (the usual case), the original price (from a sale price and percent off), or the percent off (from two prices).
- For a sale price, enter the original price and percent off. Add an extra discount if two coupons or sales stack, a sales tax percent if it applies after the discount, and a quantity for more than one item.
- Read the sale price, how much you save, the total percent off (after stacking), tax and the total for every item.
- Scroll down for a table of common discounts (10-75% off) on the price you entered.
How do you calculate 20% off (and any other percentage discount)?
Sale price = original price × (1 − percent ÷ 100). You save the difference: original price − sale price.
- $80 at 20% off: $80 × 0.80 = $64.00, saving $16.00.
- $80 at 25% off: $80 × 0.75 = $60.00, saving $20.00.
Stacked discounts: 20% then 10% is 28% off, not 30%
Two discounts multiply their remaining price factors -- they don't add their percentages. On a $100 item, 20% off leaves 80%, and a further 10% off leaves 90% of that: 0.80 × 0.90 = 0.72, so you pay 72% of the original price, which is 27.999999999999993% off overall, not 30% off. In dollars: $100.00 → $80.00 (20% off) → $72.00 (a further 10% off), a total saving of $28.00 instead of the $30.00 that simply adding the percentages would suggest.
Discount calculator with tax
Sales tax is normally charged on the price after the discount, not the original price: final price = price after discount × (1 + tax ÷ 100). $80 at 25% off is $60.00, and with 8.25% sales tax: $60.00 × 1.0825 = $64.95 ($4.95 of that is tax). Tax rates and rules (some places tax the pre-discount price, or exempt certain goods) vary by state and country, so check your receipt if the exact split matters.
Reverse: original price, or percent off, from two prices
Original price = sale price ÷ (1 − percent ÷ 100). A $60 sale price at 25% off means the original price was $60 ÷ 0.75 = $80.00.
Percent off = (original − sale) ÷ original × 100. $80 down to $60 is ($80 − $60) ÷ $80 × 100 = 25.0% off.
Discounts on multiple items
Buying more than one of the same item? Enter a quantity and the totals scale up: four items at $15.00 each with 30% off come to $10.50 each, or $42.00 for all four -- a total saving of $18.00.
Common discounts on $80.00
| % off | You save | Sale price |
|---|---|---|
| 10% | $8.00 | $72.00 |
| 15% | $12.00 | $68.00 |
| 20% | $16.00 | $64.00 |
| 25% | $20.00 | $60.00 |
| 30% | $24.00 | $56.00 |
| 40% | $32.00 | $48.00 |
| 50% | $40.00 | $40.00 |
| 60% | $48.00 | $32.00 |
| 70% | $56.00 | $24.00 |
| 75% | $60.00 | $20.00 |
Discount calculator, pay raise calculator, or salary to hourly?
- This discount calculator: the same percent maths, applied to a price instead of a paycheck.
- Pay raise calculator: how a percent, dollar or new-amount raise changes your pay in every period.
- Salary to hourly calculator: convert an annual salary to an hourly rate, or back.
Frequently asked questions
How do you calculate 20% off?
Multiply the price by (1 − 0.20) = 0.80. $80 at 20% off is $80 × 0.80 = $64.00, a saving of $16.00. In general, sale price = price × (1 − percent ÷ 100).
How do I calculate a percentage discount?
Sale price = original price × (1 − percent ÷ 100), and the amount you save = original price − sale price. $80 at 25% off is $80 × 0.75 = $60.00, saving $20.00. To find the percent off from two prices instead, use (original − sale) ÷ original × 100: from $80 down to $60 that's 25.0%.
How do two discounts stack? Is 20% off then 10% off the same as 30% off?
No -- stacked discounts multiply, they don't add. 20% off then 10% off on $100 leaves you paying 0.80 × 0.90 = 0.72, or 27.999999999999993% off overall (a $28.00 saving), not 30% off (which would be $70). The second discount applies to the already-discounted price, so it's always worth a little less in absolute terms than the first.
How do I add sales tax to a discounted price?
Apply tax after the discount, not before: final price = (price after discount) × (1 + tax ÷ 100). $80 at 25% off is $60.00, and with 8.25% sales tax that's $60.00 × 1.0825 = $64.95. Most US states calculate sales tax on the discounted price, but check your receipt or state rules if it matters for bookkeeping.
How do I find the original price from a sale price?
Divide the sale price by (1 − percent ÷ 100). A $60 sale price at 25% off means the original price was $60 ÷ 0.75 = $80.00. Switch to "Original price" mode and enter the sale price and percent to have the calculator do this for you.
How do I find the percent off from two prices?
Percent off = (original − sale) ÷ original × 100. Going from $80 to $60 is ($80 − $60) ÷ $80 × 100 = 25.0%. Switch to "Percent off" mode and enter both prices.
How do I calculate a discount for more than one item?
Enter a quantity and the calculator multiplies the per-item savings and final price. Four $15.00 items at 30% off come to $10.50 each, or $42.00 for all four, saving $18.00 in total.
Can the discount be more than 100%?
The calculator treats anything at or above 100% off as free (a $0 price after that discount); it never shows a negative price. A single discount over 100% almost never happens in a real sale, so double-check the number if you see it.
Does this work for currencies other than US dollars?
Yes -- the percentage math is the same in any currency. Amounts are displayed formatted as US dollars, but you can read every number as your own currency.
Is my data saved or sent anywhere?
Your entries are saved only in your own browser so they are there next time. Nothing is sent to our servers.