Coefficient of variation calculator

Paste your numbers, pick sample or population, and read the coefficient of variation (CV). It compares spread between data sets with different units or sizes.

ValuesSeparate numbers with commas, spaces or new lines.

Data is a

Coefficient of variation19.56151991%

As a ratio: 0.1956151991
Mean: 14
Standard deviation used: 2.738612788
Count: 5

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How to use it

Paste or type your values.
Choose sample or population.
Read the CV as a percentage, along with the mean and the standard deviation behind it.

How it works

CV = standard deviation / |mean|. The standard deviation uses a two-pass calculation (mean first, then squared deviations), which stays accurate for large values.

Worked example

Values 2, 4, 4, 4, 5, 5, 7, 9 have mean 5 and a sum of squared deviations of 32.

Population: σ = √(32 / 8) = 2, so CV = 2 / 5 = 40%
Sample: s = √(32 / 7) ≈ 2.138, so CV ≈ 42.76%

Tips

A lower CV means the values sit closer to their mean, relative to its size.
Do not use it for data such as temperatures in °C, where zero is arbitrary.

Frequently asked questions

What is the coefficient of variation?

It is the standard deviation divided by the mean, usually written as a percentage. It describes spread relative to the size of the average.

When should I use it?

To compare variability of data measured on different scales, such as the weights of mice and of elephants. It only makes sense for values measured on a ratio scale, where zero means none.

Sample or population?

Use sample when your numbers are a subset of a bigger group, which divides the squared deviations by n − 1. Use population when you have every value, which divides by n.

Why is there no result when the mean is 0?

Dividing by zero is not possible, and a CV near a zero mean becomes huge and unstable.

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All tools in this category: Math ·Updated November 3, 2026