Percentage Calculator

Switch between three common percentage questions: a percentage of a number, what percent one value is of another, and finding the total when you know a part and a percentage.

How it works

Percentages compare a part to a whole out of 100. This calculator covers the three most common percentage questions people search for: finding a percentage of a value, finding what percent one value is of another, and working backward to find the total when you already know a part and its percentage.

Formula

X% of Y = (X ÷ 100) × Y
X is what % of Y = (X ÷ Y) × 100
X is Y% of what = X ÷ (Y ÷ 100)

Worked examples

20% of 50 → 10
10 is what % of 50 → 20%
10 is 20% of what → 50

Useful notes

This tool calculates static percentage relationships, not the percentage increase or decrease between two values — that is a separate calculation.

FAQ

How do I calculate a percentage of a number?: Divide the percentage by 100 and multiply by the number. For example, 20% of 50 is (20 ÷ 100) × 50 = 10.
How do I find what percent one number is of another?: Divide the part by the whole and multiply by 100. For example, 10 is (10 ÷ 50) × 100 = 20% of 50.
How do I find the total when I know a part and a percentage?: Divide the part by the percentage expressed as a decimal. For example, if 10 is 20% of a number, the number is 10 ÷ 0.20 = 50.

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