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Math

Percentage Calculator

Calculate percentages, percentage increases, decreases, and differences instantly.

What is Percentage Calculator?

A percentage calculator helps you find what percent one number is of another, calculate a percentage of a value, or determine percentage change between two numbers. Percentages express a ratio out of 100 and are used everywhere from discounts and taxes to test scores and statistics.

How to use

  1. 1 Select the mode that matches your question: 'What is X% of Y?', '% Change', or 'X is what % of Y?'.
  2. 2 Enter the known values into the input fields.
  3. 3 The result updates instantly as you type.
  4. 4 Switch between modes to answer different types of percentage questions without clearing your inputs.

Formula

Percentage of a value: Result = (X / 100) × Y. Percentage change: Change = ((New - Old) / |Old|) × 100. Part as a percent: Percent = (Part / Total) × 100.

Example calculation

To find 15% of 200, enter 15 in the percentage field and 200 in the value field — the result is 30. To find the percentage change from 80 to 100, enter those values in the % Change tab to get +25%.

Frequently asked questions

How do I calculate 20% of a number?

Multiply the number by 0.20, or use the 'What is X% of Y?' tab and enter 20 and your number.

What is the formula for percentage change?

Percentage change = ((New Value - Old Value) / |Old Value|) × 100. A positive result means an increase; negative means a decrease.

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

Divide the part by the total and multiply by 100. For example, 30 out of 120 is (30 / 120) × 100 = 25%.

How do I add a percentage to a number?

Multiply the original number by (1 + percentage/100). For example, to add 15% to 200, calculate 200 × 1.15 = 230.

How to convert a fraction to a percentage?

Divide the numerator by the denominator and multiply the result by 100. For example, 3/4 becomes (3 / 4) × 100 = 75%.

What's the difference between percentage and percentage points?

Percentage points measure the arithmetic difference between two percentages. Going from 10% to 15% is a 5 percentage point increase, but a 50% relative increase.

Can I calculate a percentage greater than 100%?

Yes. A value can be more than 100% of another — for example, 250 is 125% of 200.