Calculations & UnitsLast updated: 2026-08-13

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

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How to use

  1. 1

    Pick a mode

    Choose "X% of total", "X as % of Y" or "increase/decrease by X%".

  2. 2

    Enter numbers

    Results update in real time as you type.

  3. 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.

All processing happens in your browser. Your files are never uploaded.

Did you know?

The % symbol is believed to come from the Italian "per cento" (for every hundred).

Optional usage measurement settings

Only with your consent, a random browser ID and tool/learning events are sent to measure return visits. This is pseudonymous measurement. Inputs, answers, keys, files and search terms are excluded. Consent expires after 90 days. Declining does not limit any feature.

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