Percentage Calculator

Three everyday percentage questions in one place: a percent of a number, one number as a percent of another, and the percent change between two numbers.

1. What is X% of a number?

Percent (%)

Of this number

Result: 36

2. One number as a percent of another

This number

Is what percent of

Result: 25%

3. Percent change

From

Result: +15% (increase)

Worked example

15% of 240: 240 × 15 ÷ 100 = 36
45 as a percent of 180: 45 ÷ 180 × 100 = 25%
Change from 80 to 92: (92 − 80) ÷ 80 × 100 = +15%, an increase

How this calculator works

Percent of: Number × Percent ÷ 100 | What percent: Part ÷ Whole × 100 | Change: (New − Old) ÷ Old × 100

Percent change is always measured against the starting (old) value, not the new one. That is why going from 80 to 92 is a 15 percent increase, while going back from 92 to 80 is a 13 percent decrease, not 15.

Common questions

What is the difference between a percent and a percentage point?

Percentage points measure the simple difference between two percents: a rate going from 5% to 7% rose by 2 percentage points. In percent terms, that same move is a 40 percent increase (2 ÷ 5 × 100). News reports mix these up often, and the difference matters.

How do I find the original number after a percent increase?

Divide by one plus the rate. If a price rose 15% to $92, the original was 92 ÷ 1.15 = $80. Subtracting 15% of $92 would give the wrong answer, because the percent was taken on the smaller original number.

General information only. Results are exact arithmetic on the numbers you enter; rounding is applied only for display. Mississippi Maple accepts no liability for decisions made using this calculator.