Percentage Calculator
Three modes for instant percentage math: X% of a total, X as a % of Y, and increase or decrease by X%.
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Result
—
Done
Percentage Calculator
Next time, open this tool from My Tools. Only the tool list is saved in this browser, not your inputs or results.
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How to use
- 1
Pick a mode
Choose "X% of total", "X as % of Y" or "increase/decrease by X%".
- 2
Enter numbers
Results update in real time as you type.
- 3
Copy the result
Copy the result and use it anywhere.
Features
- Three modes: X% of, % of, change by X%
- Real-time results with one-click copy
- All in your browser with no data sent
- Complements the discount and tax calculators
Use cases
Test scores
Work out the percentage for 72 out of 80 instantly.
Sales growth
Check month-over-month growth for your reports.
Shopping discounts
Calculate "30% off" prices on the spot.
Details
The percentage calculator handles three questions in one page: "What is X% of a total?", "What percentage is X of Y?" and "What is the result of increasing or decreasing by X%?". Use it for test scores, sales growth, discounted prices and more.
Results update in real time, so you can experiment with different numbers instantly. Everything runs in your browser and nothing is ever sent anywhere.
For specific use cases, the discount calculator and tax calculator are more specialized. This percentage calculator covers general ratio math in one place.
FAQ
What is the percentage formula?
X% of a total is total × X ÷ 100. X as a percentage of Y is X ÷ Y × 100.
How do I calculate change by X%?
Increase: original × (100 + X) ÷ 100. Decrease: original × (100 - X) ÷ 100.
How is this different from the discount calculator?
The discount calculator focuses on prices. This tool covers general ratios such as scores and growth rates.
Is my input saved?
No. Everything is computed in your browser and never saved or sent.
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Calculate tax-included and tax-excluded prices with automatic tax amounts. Supports 10%, 8% and custom rates.
All processing happens in your browser. Your files are never uploaded.
Verified: Browser tests cover 72/80=90%, a 25% increase of 80, small values, zero division, range errors, copy and English pages
Did you know?
The % symbol is believed to come from the Italian "per cento" (for every hundred).