Percentage math, computed instantly
Working out a discount, a price increase, or a markup by hand is easy to get subtly wrong. This tool computes it instantly and accurately, directly in your browser.
Using it
Five calculators sit on the page, each with its own boxes: X% of a number, X as a percent of Y, percentage change between an old and a new value, a price with a percentage taken off or added, and markup on a cost (which also shows the profit margin). Type in the one you need and read the result as you type.
Common uses
- Working out a discount at checkout, and how much it saves you.
- Calculating a price increase or decrease year over year.
- Setting a markup on a product's cost and checking the margin it leaves.
- Finding what percent one number is of another, such as a score or a share of a budget.
Percentage point versus percentage — a common mix-up
This distinction trips up a lot of people, including in professional reporting. If a rate moves from 5% to 7%, that's genuinely a 2 percentage point increase — but it's also a 40% relative increase, since 2 is 40% of the original 5. Both descriptions are accurate; they just measure different things, and mixing them up in a sentence can make a change sound far bigger or smaller than it actually is.
Markup versus margin
Markup is calculated on top of cost — a $10 item with a 50% markup sells for $15. Margin is calculated as a percentage of the selling price — that same $15 sale, with a $10 cost, has roughly a 33% margin, not 50%. The two numbers describe the same sale but from different starting points, which is exactly why they're never equal for the same transaction.
Pairs well with
For splitting a bill instead, the site's Tip Calculator handles that directly.
Frequently asked questions
+Is this calculator really free, with no sign up?
Yes. There's no account and no limit on how many calculations you can run.
+What's the difference between a percentage and a percentage point?
This trips a lot of people up. If an interest rate moves from 5% to 7%, that's a 2 percentage point increase, but a 40% relative increase (2 is 40% of 5). Both statements are true but describe different things — mixing them up is a common source of confusion, especially in financial and statistical reporting.
+How is markup different from margin?
Markup is added on top of cost (a $10 item marked up 50% sells for $15). Margin is the percentage of the selling price that's profit (that same $15 sale with a $10 cost has a 33% margin, not 50%). They're calculated from different bases, which is why the two numbers are never the same for a given price.