Multiple percentage calculations — all in one place.
Percentage problems come in more than one shape, and it's easy to blank on which formula applies to which situation. This tool covers the four calculations people run into most often: finding what a percentage of a number is, figuring out what percentage one number is of another, calculating a percentage increase or decrease between two values, and adding or subtracting a percentage from a starting amount.
Each calculator updates live as you type, so you can see the result immediately without clicking a separate button for every small change.
How do I calculate a percentage increase?
Use the "Percentage Change" section — enter the original ("from") value and the new ("to") value, and it will show you the percentage increase or decrease between them.
What's the difference between "X% of Y" and "X is what % of Y"?
The first finds a portion of a number (e.g. what is 15% of 200?). The second works backward — given two numbers, it tells you what percentage relationship they have (e.g. 30 is what percent of 200?).
Can I use this for discounts and markups?
Yes — the "Add / Subtract a Percentage" section is exactly for that: enter your starting amount, choose add or subtract, and enter the percentage.