Percentage Calculator
Two calculators in one: find X% of Y, or find what percent X is of Y.
X% of Y
15% of 80 = 12
X is what % of Y
30 is 15% of 200
This combines the two most commonly needed percentage calculations. The first works out what a given percentage of a number is (like 15% of 80). The second works out what percentage one number represents of another (like what percent 30 is of 200) — both update instantly as you type, with no need to remember the formula.
How to use it
- Use the first calculator to find X% of Y — enter both numbers.
- The result appears instantly below it.
- Use the second calculator to find what percent X is of Y.
- The percentage result appears instantly below it.
Frequently asked questions
What's the formula for 'X% of Y'?
Multiply Y by X, then divide by 100 — for example, 15% of 80 is (80 × 15) / 100 = 12.
What's the formula for 'X is what % of Y'?
Divide X by Y and multiply by 100 — for example, 30 is (30 / 200) × 100 = 15% of 200.
Can I use negative numbers or decimals?
Yes, both calculators handle decimals and negative numbers correctly.