Percentage Calculator
Four everyday percentage calculations in one place, with the working shown.
Percentages in one line
A percentage is just a fraction out of 100. 15% means 15 out of every 100, or 0.15. Most percentage questions come in four shapes, and each has its own tab above.
The four calculations
- What is X% of Y? Multiply: Y × X ÷ 100. For example 15% of 200 is 30.
- X is what percent of Y? Divide and multiply by 100: 30 ÷ 200 × 100 = 15%.
- Percentage change. (new − old) ÷ old × 100. From 80 to 100 is +25%.
- Increase or decrease by a percent. Multiply by 1 plus or minus the percent: 50 increased by 10% is 55.
A common trap
A rise of 25% followed by a fall of 25% does not return you to the start. 100 becomes 125, and 25% off 125 is 93.75. Percentage changes are always relative to the number you start from.
Frequently asked questions
How do I find the percentage difference between two numbers?
Use the % change tab: subtract the old number from the new one, divide by the old number and multiply by 100.
What is the difference between percent and percentage points?
If a rate moves from 4% to 6%, it rose by 2 percentage points, which is a 50% increase in the rate itself.
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