How do I calculate a percentage?

Divide the part by the whole and multiply by 100: (part / whole) × 100.

Percentage Calculator

Calculate what percent one number is of another, and find X% of Y.

WholePart

Percentage: 25.00%

Formula

Assumptions

Inputs are sanitized and clamped to their declared ranges; divide-by-zero is guarded. Currency math uses integer minor units; rounding uses banker's rounding (half to even).

Sources

Percent computation per the U.S. Bureau of Labor Statistics (BLS percent-change factsheet).

How it works

This calculator divides the part by the whole and multiplies by 100 to express the ratio as a percentage. The default values shown were computed at build time and are present in the page source.

Worked example

If the whole is 200 and the part is 50, then (50 / 200) × 100 = 25%.

When to use this

Use a percentage calculator to compare a part to its whole — discounts, test scores, survey results, or any ratio expressed per hundred.

Related tools

Frequently asked questions

How do I calculate a percentage?: Divide the part by the whole and multiply by 100: (part / whole) × 100.
What is 50% of 200?: 100. Half of 200 is 100.

Built and maintained by the Calculator Nova team.

AI-assisted. Formulas are unit-tested; sources cited and verified. Not individually human-reviewed. Informational only — not financial advice.