How a percentage discount is worked out
A percentage discount takes a fraction of the original price off the price. The calculation has two steps: multiply the original price by the discount percentage divided by 100 to get the amount saved, then subtract that amount from the original price to get what you pay.
For example, a 250 item with 20% off saves 250 x 20 / 100 = 50, so the final price is 200. The percentage always applies to the starting price, not to some later total, which is why a larger starting price makes the same percentage worth more money.
When a quick discount check is useful
Sale tags often show only the percentage, and the number that matters to your wallet is the final price. Checking it takes a few seconds and helps you compare two offers that are written differently, such as 15% off one item against a flat price on another.
Shop owners use the same arithmetic when setting promotional prices, and buyers use it to confirm that a checkout total matches the advertised offer. It is also a simple way to see how much a coupon is really worth before you decide whether a purchase is worth making.
How to calculate a discount with this tool
- Enter the price before the discount in the Original price box. It starts at 100.
- Enter the percentage off in the Discount (%) box. It starts at 20.
- Read the two results underneath: You save and Final price. They update as you type, so there is no button to press.
- Change either number to compare different offers.
The calculation runs in your browser and nothing is sent anywhere. For a case like 80 with 15% off, you would see a saving of 12.00 and a final price of 68.00.
Limits and common mistakes
Results are always shown with a dollar sign and two decimal places, because the tool does not have a currency setting. If you are working in another currency, just ignore the symbol and read the numbers.
Discounts do not simply add together. A 20% reduction followed by a further 10% is not 30% off: take 20% off first, then take 10% off the reduced price, which works out to 28% off the original. To model that, run the tool twice and use the first final price as the second original price. The tool does not add sales tax, so apply tax separately. If you want to work out how much one number is of another, the Percentage Calculator covers that directly.