Percentage calculator
Work out a percentage in three ways: a percent of a number, one number as a percent of another, or the whole number when you know a part and its percent. The working is shown under the answer.
Worked example
With the values shown above when the page opens:
15% of 80 is 12
- X% of Y = Y × X ÷ 100
- = 80 × 15 ÷ 100
- = 12
How it works
- A percent means "out of 100", so 15% is 15/100 or 0.15.
- To find a percent of a number, multiply the number by the percent and divide by 100.
- To find what percent one number is of another, divide the first by the second and multiply by 100.
- To find the whole when you know a part, divide the part by the percent as a decimal.
Questions
How do I find 15% of a number quickly?
Find 10% by moving the decimal point one place left, then add half of that for the other 5%. For 80: 10% is 8, 5% is 4, so 15% is 12.
Can a percentage be more than 100?
Yes. 150% of 80 is 120. It means one and a half times the number.
What is the difference between percent and percentage points?
Going from 10% to 12% is a rise of 2 percentage points, but a 20% increase in the rate itself. Use the percent change calculator for the second kind.
Related
Calculators are for learning and quick checks. Check important figures yourself, and do not rely on them for tax, legal or financial decisions.