Percentage Calculator
Three modes: X% of Y, X is what percent of Y, and percentage change between values.
About this tool
Three modes: X% of Y, X is what percent of Y, and percentage change between values. Your data never leaves your browser. Client-side processing with zero waiting. No accounts, no paywalls, no watermarks.
How to use
- 1
Type or paste your data in the input box
- 2
Choose your options and run the tool
- 3
Copy or download the result — done!
Frequently asked questions
▸Which modes does the calculator support?
Three: X% of Y (e.g. 15% of 240), X is what percent of Y (e.g. 36 is 15% of 240), and percentage change from X to Y, which labels the result as an increase or decrease.
▸How is percentage change calculated?
As (Y − X) / |X| × 100. The absolute value of the base keeps decreases labeled correctly, e.g. from 200 to 150 is a 25% decrease. A base of 0 is undefined, so no result is shown.
▸Does it handle decimals and negative numbers?
Yes. You can enter values like 2.5 or −40, and results are shown with up to four decimal places, trimmed of trailing zeros.