Math calculator

Percentage Calculator

Find a percentage of a number, compare two numbers, or calculate percent change.

Percentage

Of value

Result

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In words—

Formula(X ÷ 100) × Y

How to calculate percentages

A percentage is a fraction of 100. To find a percentage of a number, divide the percentage by 100 and multiply by the number. To find what percent one number is of another, divide the first by the second and multiply by 100.

Percentage formulas

X% of Y = (X ÷ 100) × Y

X as a percent of Y = (X ÷ Y) × 100

Percent change = ((End − Start) ÷ Start) × 100

Examples

What is 15% of 80?

(15 ÷ 100) × 80 = 12

25 is what percent of 200?

(25 ÷ 200) × 100 = 12.5%

What is the percent change from 40 to 50?

((50 − 40) ÷ 40) × 100 = 25% increase

Frequently asked questions

How do I calculate a percentage in my head?

Start with 10% by moving the decimal one place left, then scale. For example, 10% of 80 is 8, so 20% is 16 and 5% is 4. Combine these to reach most common percentages quickly.

What is the difference between percent change and percentage points?

Percent change is relative: going from 10% to 15% is a 50% increase. Percentage points are absolute: the same move is an increase of 5 percentage points.

How do I calculate a percentage decrease?

Use the percent change formula. If the result is negative, the change is a decrease. For example, going from 50 to 40 is ((40 − 50) ÷ 50) × 100 = −20%, a 20% decrease.

How do I add a percentage to a number?

Multiply the number by (1 + percentage ÷ 100). To add 8% to 250, multiply 250 × 1.08 = 270.