Discount Calculator
Calculate a sale price or a discount percentage instantly. Runs entirely in your browser. Nothing you type is ever uploaded.
What can you calculate?
SaleMath covers the two questions people look up most around a sale: what a price becomes after a percentage discount, and what percentage a sale actually represents when you know the original and sale price. Pick a mode, enter your numbers, and the result updates as you type.
Ever wonder if two stacked discounts really add up the way the sign implies? Read Why "50% Off, Then Extra 50% Off" Isn't 100% Off.
How it works
Every calculation runs directly in your browser using plain arithmetic. Nothing is sent to a server, so it works even offline once the page has loaded.
Frequently asked questions
Is this free to use?
Yes. There's no sign-up and no limit on how many calculations you run.
Do you store what I type?
No. Every calculation happens entirely client-side in your browser. See the privacy policy for details.
How is the sale price calculated?
Sale price is the original price minus the original price multiplied by the discount percentage. The amount saved is the difference between the original and sale price.
What if I know both prices but not the discount?
Switch to the "find the discount %" mode, enter the original and sale price, and it works out what percentage off that actually is.