Percentage Calculator

What is a Percentage?

In mathematics, a percentage is a number or ratio that represents a fraction of 100. It is one of the most common ways to express a dimensionless relationship between two numbers. Percentages are denoted by the symbol "%" written after the number.

How to Use This Percentage Calculator

1. What is X% of Y?

Find what a certain percentage of a number equals. Example: What is 25% of 480?

2. X is what % of Y?

Find what percentage one number is of another. Example: 120 is what percent of 200?

3. Percentage Change

Calculate how much a value has increased or decreased in percentage terms.

Percentage Formulas

Basic Percentage

X% of Y = (X ÷ 100) × Y

Percentage Change

((New Value − Old Value) ÷ Old Value) × 100

Percentage Difference

|Value 1 − Value 2| ÷ ((Value 1 + Value 2) ÷ 2) × 100

Important Notes

Percentage calculations are used everywhere — from discounts, taxes, statistics, to finance and science.
When calculating percentage change, always use the original (old) value as the base.
A 100% increase means the value has doubled. A 50% decrease means it is now half.
Percentages greater than 100% indicate growth beyond the original value.