Percentage Calculator

Answer the three everyday percentage questions in one place: a percent of a number, one number as a percent of another, and the percent change between two values.

What is X% of Y?

% of = —

X is what percent of Y?

is what % of = —

Percent change from A to B

from to = —

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How to use percentage calculator

Pick the question
Use whichever of the three rows matches what you're trying to find.
Enter your numbers
Type the values into the two fields — results appear instantly.
Read the answer
The output on the right updates live as you type.

Features

Three calculators in one

Percent-of, part-to-whole and percent-change without switching tools.

Live results

Answers recalculate on every keystroke.

Handles increases and decreases

Percent change shows a clear rise or fall between two figures.

Frequently asked questions

How is percentage change calculated?

It's (new − old) ÷ old × 100. A positive result is an increase, a negative one is a decrease.

What if I divide by zero?

If the base value is zero the percentage is undefined, so the tool shows a dash instead of a misleading number.

Can I use decimals?

Yes — all fields accept decimal numbers for precise results.