About the Percentage Calculator
Work out a percentage of a number, express one number as a percentage of another, or calculate the change between two values. Every result includes the formula so you can check the maths yourself.
How to use it
- 1Pick a modePercentage of a value, X is what percent of Y, or percentage increase/decrease.
- 2Enter the numbersResults update as you type; no submit button and no page reload.
- 3Read the workingThe formula and each intermediate step are shown beneath the answer.
Why use this percentage calculator?
- Nothing leaves your device. The work happens in your browser tab. There is no upload endpoint in this app, so your files and text cannot be stored, logged or seen by us.
- No upload wait. You skip the round trip to a server entirely. Results are limited by your own CPU, not by network speed or queue size.
- Free, no account, no quotas. No sign-up wall, no watermark, no daily limit. Optional accounts only exist to save favourites and presets across devices.
Frequently asked questions
Is my calculation safe to use here?
Yes. This tool runs entirely in your browser using JavaScript. Nothing you paste or open is sent to a server, and the page keeps no copy after you close it.
Do I need to create an account?
No. Every tool is fully usable without signing in. An account only adds saved favourites and reusable presets.
Does it work on a phone?
Yes. The interface is mobile-first with large touch targets and a stacked layout, so it works on phones and tablets as well as desktops.
How do I calculate a percentage increase?
Subtract the original value from the new value, divide by the original value, then multiply by 100. For example, 120 from 100 is (120 − 100) ÷ 100 × 100 = 20%.
What is the difference between percent and percentage points?
A change from 10% to 12% is two percentage points but a 20% relative increase. News reports often mix the two, so check which one a claim uses.