Percentage Calculator
Calculate percentages, percent of a number and percentage change.
How to use the Percentage Calculator
Pick the question you are answering
Use the first row for a percentage of a number, the second for what percent one value is of another, the third for a change between two numbers.
Enter your values
Type the numbers into the fields for that row.
Read the result
The answer updates as you type, so you can adjust the inputs and compare straight away.
About the Percentage Calculator
Percentages are simple until you have to do one quickly and get it right. There are really three separate questions people mean when they say percentage, and mixing them up is the usual source of an embarrassing answer: what is 15% of 240, what percent of 240 is 36, and what is the change from 240 to 276. This calculator does all three at once so you do not have to work out which formula you needed.
The third is the one that trips people most often. Percentage change is measured against the starting value, not the ending one, which is why a 50% fall needs a 100% rise to get back to where it began. The same asymmetry is behind a lot of misleading statistics — a stock that drops 40% and then gains 40% has not recovered, it is down 16%.
The everyday uses are the ordinary ones: a discount in a sale, a tip on a bill, a commission on a sale, a tax rate applied to an invoice, a grade expressed as a mark out of a total, or a year-on-year change in a report. Everything is calculated in your browser, so nothing you type is sent anywhere or stored.
Frequently asked questions
- How do I calculate a percentage of a number?
- Multiply the number by the percentage and divide by 100. For 15% of 240: 240 x 15 / 100 = 36.
- How do I calculate percentage increase?
- Subtract the old value from the new one, divide by the old value, then multiply by 100. From 240 to 276 is a 15% increase.
- Why does a 50% loss need a 100% gain to recover?
- Because change is measured against the starting value. Falling from 100 to 50 is a 50% drop, but climbing from 50 back to 100 is a 100% rise.