Percentage Calculator
Solve any percentage problem: percent of, percent change, and more.
Quick answer
To find P percent of a number, multiply the number by P ÷ 100. To find what percentage one number is of another, divide the part by the whole and multiply by 100. For percentage change, divide the difference (new − old) by the old value and multiply by 100.
What is X% of Y?
36
X is what percent of Y?
20%
Percent change
25%
increase
The three percentage problems
Nearly every percentage question is one of three forms. X% of Y multiplies: 15% of 240 is 0.15 × 240 = 36. X as a percent of Y divides: 30 ÷ 150 = 0.20, so 20%. Percent change compares the difference to the starting value: (150 − 120) ÷ 120 = 25% increase.
A common pitfall
Percent change is always measured against the starting value, which is why a 50% drop needs a 100% gain to recover: from 100 down to 50 loses 50 of 100, but climbing back gains 50 of 50. Percentage points and percent are different too — moving from 10% to 15% is a rise of 5 points, but a 50% relative increase.
Frequently asked questions
- How does the Percentage Calculator work?
- To find P percent of a number, multiply the number by P ÷ 100. To find what percentage one number is of another, divide the part by the whole and multiply by 100. For percentage change, divide the difference (new − old) by the old value and multiply by 100.
- Is the Percentage Calculator free to use?
- Yes. The Percentage Calculator is completely free, runs entirely in your browser, and requires no account or sign-up. Your inputs never leave your device.
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