Percentage Calculator
Calculate percentages 6 ways: X% of Y, X is what % of Y, % increase/decrease, % of total, tip %, tax %. With copy, history, and CSV export. 100% private.
About Percentage Calculator
Calculate percentages 6 ways: X% of Y, X is what % of Y, % increase/decrease, % of total, tip %, tax %. With copy, history, and CSV export. 100% private. Everything runs locally in your browser — your data never leaves your device.
How to use
- Enter your input in the tool above.
- Adjust any options to your preference.
- Use the Copy or Download buttons to save the result.
- Everything happens locally — your data never leaves your browser.
FAQ
How is percentage calculated?
Percentage = (Part / Whole) * 100. To find X% of Y, multiply X/100 * Y. To find what percent X is of Y, divide X/Y * 100. Percent change = (New - Old) / |Old| * 100.
What extra features does this tool have?
Extras: (1) 6 calculation modes in one tool, (2) % increase AND decrease side-by-side, (3) Tip + tax combined calc, (4) Multi-item percentage split, (5) Calculation history (last 10, localStorage), (6) CSV export of history, (7) Fraction-to-percent converter, (8) Reverse percentage (find original from final + %), (9) Compound percent change (chained %), (10) Percent error calculator, (11) Copy individual results, (12) Decimal precision control (0-6).
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