Coefficient of Variation Calculator
Enter a list of numbers to find the standard deviation as a percentage of the mean.
This result is an estimate only. Double-check important figures before relying on them.
How it is calculated
- Mean = sum ÷ count
- Sample standard deviation = √(sum of squared deviations ÷ (n − 1))
- CV = standard deviation ÷ |mean| × 100
For the standard deviation on its own, use the standard deviation calculator.
Worked example
For 10, 12, 23, 23, 16, 23, 21, 16:
- Mean = 18, sample standard deviation = 5.2372
- CV = 5.2372 ÷ 18 × 100 = 29.10%
Why your number may differ
CV is only meaningful for data measured on a ratio scale with a true zero. It gets unstable and misleading when the mean is close to 0.
Frequently asked questions
What is the coefficient of variation?
It is the standard deviation divided by the mean, as a percentage. It shows how big the spread is relative to the average.
Why use it?
It lets you compare the spread of data measured in different units or at different scales, such as the price of two products.
Sample or population?
Use the sample value when your data is a sample of a larger group, which is the usual case. Use the population value when you have every member.