Discount Calculator
Work out the sale price and how much you save — with one discount, or an extra discount on top.
Discount:
Price after first discount:
Extra discount:
Sale price:
You save:
The calculation happens in your browser — the prices you enter are not sent anywhere.
How to use the discount calculator
Enter the original price, pick a discount, and the calculator works out the sale price and how much you save straight away. The result updates the moment you change a number, so you can compare discounts as quickly as you can type them. You can use it in a shop, when a sale has an extra discount on top, or before a big purchase when you want to know the real price. There is nothing to install and no sign-up, and the calculation happens in your browser.
- Enter the original price — the price before any discount, in dollars.
- Choose a discount — tap a preset percentage (10%, 20%, 25%, 30% or 50%) or type your own percentage.
- Add an extra discount if there is one — for example a coupon worth 10% off the sale price. Leave it at 0 if there is only one discount. Then read the sale price and the amount you save.
Worked example: $100 at 20% off
Take a $100 item at 20% off. The discount is $100 times 20 divided by 100, which is $20.00. The sale price is $100 minus $20.00, which is $80.00, and the amount saved is $20.00. Try it in the calculator above: enter 100 as the original price, choose the 20% preset, and leave the extra discount at 0. You will see a discount of $20.00, a sale price of $80.00, and $20.00 saved. The same maths works for any price: a $250 item at 30% off gives a discount of $75.00, a sale price of $175.00, and $75.00 saved.
How stacked discounts work
A second discount is worked out on the price after the first discount, not on the original price. That is why two discounts do not simply add up. Take an $80 item with 25% off and an extra 10% off on top. The first discount is $80 times 25 divided by 100, which is $20.00, leaving a price of $60.00. The extra discount is 10% of $60.00, which is $6.00, not 10% of $80. So the sale price is $60.00 minus $6.00, which is $54.00, and the total saved is $80.00 minus $54.00, which is $26.00. If the two percentages simply added up, 25% plus 10% would be 35% off, which would be $28.00 off and a sale price of $52.00 — but shops apply each discount in turn, so the real saving is $26.00. This calculator shows the saving from each discount separately, so you can see exactly where the money goes.
When a discount cannot be more than 100%
A discount of 100% means the item is free. A discount over 100% would make the price less than zero, which is not possible, so the calculator will ask you to use a smaller percentage if you try it. A discount of 0% means no discount at all, and the sale price is the same as the original price. The extra discount follows the same rule: it is a percentage of the price after the first discount, so it also cannot be 100% or more.
Frequently asked questions
How is a discount calculated?
A discount is the original price times the discount percentage divided by 100. The sale price is the original price minus the discount, and the amount saved is the same as the discount. For example, a $100 item at 20% off has a discount of $20.00, a sale price of $80.00, and $20.00 saved.
What is the difference between % off and $ off?
A percentage discount is a share of the price, so the amount saved grows with the price: 20% off $100 is $20.00, and 20% off $250 is $50.00. A dollar-off discount is a fixed amount whatever the price is, so $20 off a $100 item and $20 off a $250 item both save $20. This calculator works with percentages: enter the percentage off and it works out the dollar amount for you.
Do discounts stack?
Yes, here they do. If there is an extra discount, it is applied to the price after the first discount, not to the original price. So two discounts do not simply add up: 25% off plus an extra 10% off an $80 item gives a sale price of $54.00, not the $52.00 that 35% off would give.
How do I work out the original price from a sale price?
Divide the sale price by one minus the discount as a decimal. For example, an item on sale for $80 at 20% off came from an original price of $80 divided by 0.8, which is $100. If there was an extra discount as well, work backwards through each discount in turn.
Can a discount be more than 100%?
No. A discount of 100% means the item is free, and a discount over 100% would make the price negative, which is not possible. If you enter 100% or more in this calculator, it will ask you to use a smaller percentage.