Discount Calculator
Find a sale price and the amount saved, or work back from a sale to the original price.
Add a tax rate (optional)
Add a tax rate (optional)
Pick a question and fill both fields — the answer appears as you type.
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How to use it
- 1
Enter the original price and the discount percent, or the sale price and the discount if you are working backwards.
- 2
Read the amount saved and what you pay, with the formula underneath.
- 3
If you need to add tax, type the rate yourself. This page does not look up a local rate.
A discount is a decrease, in shopping language
The amount saved is the original price times P/100. The sale price is the original minus the amount saved, which is the same arithmetic as “decrease the price by P%.” To recover an original price from a sale price, divide the sale price by (1 − P/100). A 100% discount leaves no original to recover.
Two separate 20% discounts in a row are not 40% off. This page applies a single discount. Tax is only included when you type a rate; there is no built-in list of state or national rates.
Other percentage tools
Frequently asked questions
How is 20% off 150 calculated?
The saving is 150 × 0.20 = 30, so you pay 120. Working backwards from a sale price of 120 at 20% off, divide 120 by 0.80 to get the original 150.
Is this the same as the decrease calculator?
The numbers match. This page uses shopping words (original, off, sale price) and can add a tax rate you type. The decrease page is the general math form.
Do you include sales tax automatically?
No. If you want tax included, type the rate yourself. This site does not ship a table of regional tax rates.
Can I stack two coupons?
Not as a single 40% off. Two 20% discounts applied one after the other leave 64% of the original, which is 36% off in total, and the order can matter. This version applies one discount only.
Are prices rounded like money?
Yes. Money results default to two decimal places, rounding half-up away from zero. You can show eight places if you need the unrounded remainder.