How do I calculate X% of Y?

Multiply Y by X divided by 100. For example, 20% of 150 is (20 ÷ 100) × 150 = 30. The first calculator above does this live as you type.

How do I find what percent X is of Y?

Divide X by Y and multiply by 100. For example, 30 is what percent of 150? (30 ÷ 150) × 100 = 20%. Use the second calculator for this.

How is percentage increase or decrease calculated?

Subtract the original value from the new value, divide by the absolute value of the original, then multiply by 100: ((Y − X) ÷ |X|) × 100. A positive result is an increase, a negative result is a decrease.

Is my data sent anywhere?

No. Every calculation happens locally in your browser using JavaScript — nothing you type is transmitted or stored.

PERCENTAGE CALCULATOR

Three percentage calculators in one — find X% of Y, what percent X is of Y, or the percentage change from X to Y. Nothing leaves your browser.

X% of Y

X (%)

% of

Result30

X is what percent of Y?

is % of

Result20%

% increase / decrease from X to Y

From (X)

To (Y)

Result+25%

How to use the percentage calculator

1
Pick the calculation you need: X% of Y, X as a percent of Y, or the percentage change from X to Y.
2
Type your numbers into the fields.
3
Read the result instantly — it updates as you type, no button to press.

Questions

How do I calculate X% of Y?: Multiply Y by X divided by 100. For example, 20% of 150 is (20 ÷ 100) × 150 = 30. The first calculator above does this live as you type.
How do I find what percent X is of Y?: Divide X by Y and multiply by 100. For example, 30 is what percent of 150? (30 ÷ 150) × 100 = 20%. Use the second calculator for this.
How is percentage increase or decrease calculated?: Subtract the original value from the new value, divide by the absolute value of the original, then multiply by 100: ((Y − X) ÷ |X|) × 100. A positive result is an increase, a negative result is a decrease.
Is my data sent anywhere?: No. Every calculation happens locally in your browser using JavaScript — nothing you type is transmitted or stored.