Percentage Calculator

Calculate percentages three ways: X% of Y, X is what % of Y, or percent change between two numbers.

Try:
X% of Y inputs

Result

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The formula

result=X100×Y\text{result} = \frac{X}{100} \times Y

result = (X / 100) * Y

X
The percentage
Y
The base number

Methodology & accuracy

Every result is computed in your browser from a transparent, auditable formula (result = (X / 100) * Y). We show the math so you can verify it — no black boxes.

Last reviewed:

Frequently asked questions

How do I calculate what percent one number is of another?+

Divide the part by the whole, then multiply by 100. For example, 30 out of 150 is (30 / 150) × 100 = 20%.

How do I calculate percentage change?+

Subtract the old value from the new value, divide by the old value, then multiply by 100. A rise from 80 to 100 is ((100 − 80) / 80) × 100 = 25%.