Percentage Calculator

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Processing & privacy details

This transformation does not submit its input or output to Laravel. Copying or downloading moves results outside this tab. See the privacy policy for the site's wider data practices and limits.

Equation: (X ÷ 100) × Y

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How to calculate percentages

Choose a mode, enter both numbers, then press Calculate or Enter. Editing either input or changing mode clears the previous result so you cannot copy a stale answer.

  • X% of Y: (X ÷ 100) × Y. For example, 15% of 240 = 36.
  • X is what percent of Y? (X ÷ Y) × 100. For example, 120 ÷ 480 × 100 = 25%. Y cannot be zero.
  • Percentage change: ((new − old) ÷ old) × 100. From 240 to 300 is +25%; reversing the direction, from 300 to 240, is −20%. From 240 to 0 is −100%. The original value is always the base.

Rounding and limitations

Results are approximate: browser floating-point arithmetic is used without intermediate rounding, and display is rounded to 10 significant digits. Very small or large results use scientific notation. Values outside the browser’s numeric range, overflow and nonzero results that underflow to zero are rejected rather than shown as a valid zero.

Use decimal numbers with a dot, optionally signed or in scientific notation (for example, −12.5 entered as -12.5, or 1e6). Commas, percent signs, fractions, hexadecimal and other expressions are not accepted. The first two modes allow negative values. Percentage change requires a positive original value and a non-negative new value; zero or negative starting baselines are unsupported.

Percentage change is relative, not a percentage-point difference: moving from 20% to 30% is +50% relative change but +10 percentage points. This calculator does not provide currency, tax, APR or investment advice. Convert measurements to the same units first using the related converters below.

Method reference: relative change and percentage difference.

Content modified : explanation checked against the implementation and linked references; examples covered by automated reference checks. Human editorial sign-off is pending. Maintenance and correction tracking: michaeldaly / UsefulUtilities. Report a correction with the page, non-sensitive input and expected result, or contact the project.

Calculate X% of Y, X as a percentage of Y, or percentage change from an original value, locally in your browser.