Coefficient of Variation (CV) Calculator
Paste a data set to find its coefficient of variation, the standard deviation relative to the mean. The CV is unitless, so it lets you compare the spread of data sets measured on different scales.
How to calculate the coefficient of variation
- Enter your numbers separated by commas, spaces or new lines.
- Choose the sample or population standard deviation.
- Read the CV as a ratio and as a percentage.
Examples
Sample CV of a small data set
2, 4, 4, 4, 5, 5, 7, 9
CV = 0.4276, or 42.76%
Frequently asked questions
What is the coefficient of variation?
The CV is the standard deviation divided by the mean. It expresses spread relative to the average, usually as a percentage, and has no units.
Why use the CV instead of the standard deviation?
Because it is unitless, the CV lets you compare variability across data sets with different units or very different averages, which a raw standard deviation cannot.
Should I use the sample or population CV?
Use the sample CV (the default) when your data is a sample of a larger group, and the population CV when your data covers the entire group.
Why can't the mean be zero?
The CV divides the standard deviation by the mean. When the mean is zero that division is undefined, so the CV cannot be computed.
Can the coefficient of variation be negative?
For all-positive data it is non-negative. With a negative mean the ratio can be negative, so the absolute value is usually reported for interpretation.
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