How a discount is calculated
A discount is a percentage of the original price. To get the sale price, you multiply the original price by what is left after the discount. 20% off leaves 80%, so an $80 jacket costs 80 × 0.80 = $64 and your savings are $16. The same formula works backwards: if you know the original price and the sale price, the difference divided by the original price is the percent off.
Common discounts on $50 and $100
A quick reference for the percentages you see most on price tags. The savings on $100 are always the percentage in dollars, which makes $100 a handy number for checking a deal in your head.
| Discount | Sale price on $50 | You save | Sale price on $100 | You save |
|---|---|---|---|---|
| 10% off | $45.00 | $5.00 | $90.00 | $10.00 |
| 15% off | $42.50 | $7.50 | $85.00 | $15.00 |
| 20% off | $40.00 | $10.00 | $80.00 | $20.00 |
| 25% off | $37.50 | $12.50 | $75.00 | $25.00 |
| 30% off | $35.00 | $15.00 | $70.00 | $30.00 |
| 40% off | $30.00 | $20.00 | $60.00 | $40.00 |
| 50% off | $25.00 | $25.00 | $50.00 | $50.00 |
| 60% off | $20.00 | $30.00 | $40.00 | $60.00 |
| 70% off | $15.00 | $35.00 | $30.00 | $70.00 |
| 75% off | $12.50 | $37.50 | $25.00 | $75.00 |
Stacked discounts: why 20% plus 10% is not 30%
Stores often stack offers: 20% off everything, then an extra 10% at checkout, sometimes called a double discount. The second percentage is taken from the price that is already reduced, not from the original price. On an $80 item, 20% off gives $64. The extra 10% is 10% of $64, which is $6.40, so you pay $57.60. That is 28% off in total, not 30%.
| Discounts | Looks like | Real total |
|---|---|---|
| 20% then 10% | 30% | 28% |
| 25% then 25% | 50% | 43.75% |
| 30% then 20% | 50% | 44% |
| 40% then 10% | 50% | 46% |
| 50% then 20% | 70% | 60% |
| 50% then 50% | 100% | 75% |
The order of percentage discounts does not matter: 10% then 20% gives the same price as 20% then 10%. The order does matter once a fixed coupon is involved. A $10 coupon before 20% off saves you $2 more than the same coupon after it, because the 20% is then taken from a lower price.
Black Friday and sale shopping tips
- Check the original price. A big percent off a price that was raised a week ago is not a deal. Price history tools and screenshots of earlier prices help.
- Compare the final price, not the percentage. 40% off at one store can still cost more than 25% off at another. Put both into the calculator.
- Read stacking rules. Many stores exclude sale items from extra coupons or allow only one code per order.
- Count shipping and tax. Add your sales tax rate above and remember shipping, which can wipe out a small discount.
- Set a budget first. Savings only count on things you meant to buy anyway.
How to use the discount calculator
- 1Pick a mode: one percent off, stacked discounts, or find the discount from two prices.
- 2Enter the original price and the discount, or tap one of the common rates. Add a coupon or your sales tax rate if you have one.
- 3Read the sale price, what you save and the total discount. Copy the result or a link to share the deal.
Frequently asked questions
How do I calculate the percent off a price?
Multiply the original price by the discount as a decimal and subtract the result. 25% off $60 is 60 × 0.25 = $15 off, so you pay $45. A shortcut is to multiply by what is left: 60 × 0.75 = $45.
Is a coupon applied before or after the percent off?
It depends on the store, and the order changes the price. Most stores take the percentage off first and then subtract a dollar coupon, which is what this calculator does. Taking $10 off first and then 20% gives a slightly lower price, so check the fine print if the difference matters.
Is sales tax charged on the original price or the sale price?
In most US states, sales tax is charged on the price after store discounts and store coupons, so a discount also lowers the tax. Manufacturer coupons are often taxed on the price before the coupon. Enter your local rate to see the total at the register.
How do I find the original price from a sale price?
Divide the sale price by 1 minus the discount as a decimal. A $60 item marked 25% off was $60 ÷ 0.75 = $80 before the sale. Subtracting 25% from $60 and adding it back does not work, because the percentage is based on the original price.
Are two discounts of 25% the same as 50% off?
No. The second 25% comes off a price that is already 25% lower, so together they take off 43.75%. On a $100 item that is $56.25 instead of $50. Use the Stacked discounts mode to see the exact total for any combination.