Percentage Calculator
Calculates X% of Y, what percent X is of Y, and the percentage change between two numbers, all updating live.
What is X% of Y?
% of
=
30
X is what percent of Y?
is what % of
=
20%
Percentage change from X to Y
to
=
+20%
Percentage Calculator — Free Online Tool
Calculates X% of Y, what percent X is of Y, and the percentage change between two numbers, all updating live.
How to use the Percentage Calculator
- Open the tool above — it runs entirely in your browser, so your input never leaves this page.
- Paste or type your input into the field, then press the relevant button (e.g. Encode / Decode, Generate, or Convert).
- Copy the result from the output area with the copy button orCtrl/Cmd + C.
- No signup, no upload, and no tracking — repeat as often as you need.
Frequently asked questions
Is the Percentage Calculator free to use?
Yes. The Percentage Calculator is completely free, with no signup, no ads inside the tool, and no hidden limits.
Does the Percentage Calculator upload my data?
No. The Percentage Calculator processes everything locally in your browser. Your input is never sent to a server, so it stays private even on shared devices.
Does the Percentage Calculator work offline?
After the page loads, the Percentage Calculator runs entirely in your browser, so it keeps working without a network connection.
Free & private — why use this Percentage Calculator
The Percentage Calculator runs 100% client-side in your browser. Your data is never uploaded to a server, no account is required, and the tool is completely free. It works offline once the page has loaded and is part of a growing collection of privacy-first developer utilities.