Percentage Calculator

Three percentage calculators in one — percentage of a number, "X is what % of Y", and percentage change. Answers appear the moment you type.

Live — answers appear as you type

Percentage Formulas with Examples

1. Percentage of a number

Result = Number × Percent ÷ 100

Example: a 15% tip on a 60 bill → 60 × 15 ÷ 100 = 9.

2. X is what percent of Y

Percent = X ÷ Y × 100

Example: you scored 42 out of 50 → 42 ÷ 50 × 100 = 84%.

3. Percentage change

Change % = (New − Old) ÷ Old × 100

Example: price rose from 80 to 100 → (100 − 80) ÷ 80 × 100 = +25%. Note that a 25% increase followed by a 25% decrease does not return to the original value — percentages are always relative to the starting number.

Everyday Uses

  • Shopping: work out discounts and final sale prices.
  • Finance: interest rates, returns, tax and fee calculations — see also our Compound Interest Calculator and EMI Calculator.
  • School & work: exam scores, growth metrics, KPI changes.
  • Health: body-fat percentage, calorie targets, dosage proportions.

Frequently Asked Questions

How do I calculate a percentage of a number?
Multiply the number by the percentage and divide by 100. For example, 15% of 200 = 200 × 15 ÷ 100 = 30.
How do I calculate percentage change?
Percentage change = (New Value − Old Value) ÷ Old Value × 100. A positive result is an increase; a negative result is a decrease.
How do I find what percent one number is of another?
Divide the first number by the second and multiply by 100. For example: 30 ÷ 200 × 100 = 15%, so 30 is 15% of 200.