Percentage Calculator
Use this percentage calculator to find a percentage of a number, compare two values or measure the change between an old figure and a new one. Enter the numbers that match your question and choose the calculation you need.
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How it works
A percentage is a fraction out of 100. The core formulas are:
- X% of Y = (X ÷ 100) × Y
- X is what percent of Y = (X ÷ Y) × 100
- Percentage change = ((New − Old) ÷ Old) × 100
Example: 20% of 150 = (20 ÷ 100) × 150 = 30. A change from 80 to 100 is ((100 − 80) ÷ 80) × 100 = 25% increase.
How to use the Percentage Calculator
Start by identifying the type of percentage question you are asking. You may want to find a portion of a number, work out what percentage one number represents or compare an increase or decrease. Enter the values in the boxes and check the result before rounding it for your own use.
Percentages are useful for discounts, marks, changes in prices and many other everyday comparisons. If the original value is zero, a percentage change cannot be calculated in the usual way.