Percentage Calculator
Work out what X% of Y is, what percentage X is of Y, or the percentage change between two numbers.
This calculator provides estimates only, for general information and entertainment purposes. It isn't professional advice — confirm anything important independently before relying on it.
Put this calculator on your own website
Embed it as a lead magnet and capture visitor emails.
How this calculator works
A percentage is just a fraction out of 100 — "20%" means 20 out of every 100. This calculator covers the three questions people actually search for: finding X% of a number, working out what percent one number is of another, and finding the percentage change between two numbers.
"What is X% of Y?" multiplies Y by X divided by 100. For example, 20% of 200 is (20 ÷ 100) × 200 = 40.
"X is what percent of Y?" divides X by Y and multiplies by 100. For example, 40 is what percent of 200? (40 ÷ 200) × 100 = 20%.
"Percentage change from X to Y" measures how much a number moved, relative to where it started: (Y − X) ÷ X × 100. Going from 200 to 240 is a 20% increase; going from 200 to 160 is a 20% decrease. This is the calculation behind price rises, discounts, pay rises and growth rates.
Frequently asked questions
- How do I calculate a percentage increase?
- Subtract the original number from the new number, divide by the original number, then multiply by 100. Use the "Percentage change" mode above and enter the original value as X and the new value as Y.
- Why is percentage change based on the original number, not the new one?
- Because "change" is measured relative to where you started. A move from 50 to 100 is a 100% increase, but the reverse move from 100 to 50 is only a 50% decrease — the same 50-point gap is a different percentage each way because the base (X) is different.
- What's the difference between percentage points and percent?
- A percentage point is a simple difference between two percentages (e.g. going from 40% to 50% is a 10 percentage point rise), while a percentage change expresses that same move relative to the starting value (a 25% increase, since 10 ÷ 40 = 25%).