Three percentage modes on one page: X% of Y, what percent X is of Y, and percent change between numbers.
Pick the question, type two numbers, read the answer.
Choose the card that matches your question — "X% of Y", "X is what % of Y" or percent change.
Type your two numbers into the inputs.
The answer updates live as you type.
Percent change also tells you if it is an increase or a decrease.
Built for speed, privacy and reliability — on any device.
X% of Y, "X is what percent of Y", and percent change — all on one page.
Answers update as you type — no calculate button needed.
Percent change automatically tells you which direction the numbers moved.
Every calculation runs locally — nothing is sent anywhere.
No account, no limits.
Multiply Y by X and divide by 100. The first card does this instantly — 20% of 150 is 30.
Divide X by Y and multiply by 100. The second card handles it — 30 is 20% of 150.
Subtract the old value from the new one, divide by the old value and multiply by 100. The tool labels the result as an increase or decrease.
No. All math runs in your browser.
The tool works in all modern browsers including Google Chrome, Mozilla Firefox, Microsoft Edge, Safari and Opera. We recommend keeping your browser up to date for the best experience.
Step-by-step guide with screenshots and tips.
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Read guide →Step-by-step guide with screenshots and tips.
Read guide →Step-by-step guide with screenshots and tips.
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