Here is how to calculate percent off a price without doing the maths in your head. Enter the original price and the percentage, and you get the sale price and your exact savings, with optional sales tax on top.
Results update automatically as you type.
How to Calculate Percent Off a Price
Multiply the price by the percent as a decimal to get the saving, then subtract the saving from the price. For 40 percent off 50 dollars, $50 × 0.40 = $20 saved, so you pay $30. Sales tax, if any, is then added to that $30, not to the original $50.
- Turn the percent into a decimal: 40% = 0.40.
- Multiply by the price: $50 × 0.40 = $20.
- Subtract the saving: $50 − $20 = $30.
| Deal | You save | You pay |
|---|---|---|
| 40% off $50 | $20 | $30 |
| 20% off $100 | $20 | $80 |
| 15% off $40 | $6 | $34 |
| 40% off $200 | $80 | $120 |
The Sale Price Formula
Formula: Amount Saved = P × (d ÷ 100); Sale Price = P − Amount Saved; Final Price = Sale Price × (1 + t ÷ 100)
- P: the original price before the percent off is applied
- d: the percent off, either a preset (10%, 25%, 50%, 70%) or a custom value you type in
- t: an optional sales tax percentage, applied to the price after the discount
Example Scenarios
| Original Price | Percent Off | Sales Tax | Final Price |
|---|---|---|---|
| $60.00 | 15% | 0% | $51.00 |
| $200.00 | 40% | 0% | $120.00 |
| $150.00 | 25% | 6% | $119.25 |
| $45.00 | 10% | 5% | $42.53 |
| $300.00 | 50% | 0% | $150.00 |
How to Calculate Percentage Discount from Original Price
Divide the amount saved by the original price and multiply by 100. An item cut from $99 to $79 saves $20, and 20 ÷ 99 × 100 is about 20% off. The calculator works forward from a percentage, so do this step by hand.
Things That Trip People Up at the Till
Shop signs are designed to look generous, so the result is only as good as the number you feed in.
- Stacked discounts do not add up. 20% off followed by an extra 10% off is 28% off in total, not 30%, because the second cut applies to the already reduced price. Run the numbers twice in a row to see it.
- Check which price the percentage applies to. "Up to 50% off" may cover only a few items.
- Store discounts are normally taxed on the reduced price, but the rules for manufacturer coupons vary by state.
Fixed-dollar coupons behave differently from percentages. On cheap items the dollar coupon often wins, while on expensive ones the percentage is usually better. The percentage article on Wikipedia explains the underlying maths if you want to check a result by hand.
Common questions about percent off
How much is 40 percent off 50 dollars?
40% of $50 is $20, so the sale price is $30 before tax. Enter 50 as the price and pick 40% to get the same answer.How do you calculate 20 percent off 100?
Multiply 100 by 0.20 to get 20, then subtract it from 100. The sale price is 80.How much is 15 percent off 40 dollars?
15% of $40 is $6, so you pay $34 before tax.Can this calculator find the percent off between two prices?
Not automatically. It goes from a price and a known percentage to a final price. To find the percent off between an original and a sale price, divide the amount saved by the original price and multiply by 100.Is sales tax calculated on the original price or the reduced price?
On the reduced price. The calculator applies your percent off first, then works out tax on that lower amount, which matches how most retail checkouts handle discounted items.Do the 10%, 25%, 50% and 70% buttons limit what I can enter?
No, they are shortcuts. You can type any custom percent off, including decimals like 12.5%, into the custom field below the presets.Related Calculators
Working from a fixed markdown instead of two prices? Use the calculator to find your final price after a discount and tax. If you need to figure out tax on a purchase separately, the sales tax calculator handles that on its own, and shoppers outside the US can check the GST / VAT calculator for local tax rules. For a related estimate, try the Etsy Title Character Counter.