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Percentage Calculator

Every common percentage question in one place: what is X% of Y, what percent is X of Y, and by what percent did a value increase or decrease. Results update live as you type — with the formula shown so you can check the math.

🔒 100% private — files never leave your browser

1. What is X% of Y?

% of = —

2. X is what percent of Y?

of = —

3. Percentage change from X to Y

→ = —

How to use the Percentage Calculator

  1. 1 Pick the question you need: "X% of Y", "X is what % of Y", or "% change from X to Y".
  2. 2 Type your two numbers — the answer appears instantly as you type.
  3. 3 Check the formula line to see exactly how the result was computed.

Frequently asked questions

How do I calculate a percentage of a number?

Multiply the number by the percentage and divide by 100. For example, 15% of 80 = 80 × 15 ÷ 100 = 12. The calculator does this instantly and shows the formula.

How is percentage change different from percentage difference?

Percentage change compares a new value to the original: (new − old) ÷ old × 100. It is positive for increases and negative for decreases — that is what the third calculator computes.

Does it work with decimals and negatives?

Yes. Type any real numbers — decimals and negative values are handled, and division by zero is caught with a clear message.

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