How do I find what percentage one number is of another?

Divide the first number by the second and multiply by 100. For example, 30 is what percent of 150? 30 ÷ 150 × 100 = 20%.

How is percentage increase or decrease calculated?

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

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Math & Statistics

Percentage Calculator

Three calculators in one: find a percentage of a number, work out what percent one number is of another, and calculate percentage increase or decrease.

20% of 150 is

Formula—

Result—

Visual

The part compared against the whole. Updates as you change the inputs.

How it works

A percentage is a fraction out of 100. The three modes of this calculator cover the questions people ask most often.

X% of Y = (X ÷ 100) × Y
X is P% of Y → P = (X ÷ Y) × 100
Change = ((new − old) ÷ old) × 100

Worked examples

Question	Answer
20% of 150	30
30 is what % of 150	20%
Change from 80 to 100	+25%
Change from 100 to 80	−20%

Frequently asked questions

How do I calculate a percentage of a number?

Divide the percentage by 100 and multiply by the number: 20% of 150 = 0.20 × 150 = 30.

How do I find what percent one number is of another?

Divide the first by the second and multiply by 100: 30 ÷ 150 × 100 = 20%.

How is percentage change calculated?

Subtract old from new, divide by old, multiply by 100. From 80 to 100 is +25%.