Coefficient of Variation Calculator
Refuses the cases where it means nothing.
Work out Coefficient of Variation. Refuses the cases where it means nothing. Refuses out-of-range input instead of guessing.
Comma or space separated. Needs a ratio scale with a true zero.
Coefficient of variation
6.676%
Very low variability relative to the mean
The coefficient of variation is the standard deviation as a fraction of the mean, which makes spread comparable across quantities measured in completely different units — the variability of rainfall against the variability of income, say. It only means anything on a ratio scale with a true zero. Applied to temperatures in Celsius it produces a number that changes when you convert to Fahrenheit, which is a clear sign it is measuring nothing, so that case is flagged here rather than answered. It also breaks down as the mean approaches zero, where the ratio explodes without the underlying spread changing at all. Data straddling zero is refused for the same reason.
How the Coefficient of Variation Calculator works
Standard deviation as a percentage of the mean, which makes spread comparable across quantities in completely different units. It only means anything on a ratio scale with a true zero — and this says so when your data does not qualify.
Also known as: relative standard deviation · cv percentage calculator · compare variability across units · is my cv too high
Frequently asked questions
What is the coefficient of variation?
The standard deviation divided by the mean, usually shown as a percentage. It expresses variability relative to size, so a spread of 5 around a mean of 10 is far more variable than the same spread around 1,000.
When is the coefficient of variation meaningless?
On interval scales without a true zero. Applied to temperatures in Celsius it produces a number that changes when you convert to Fahrenheit — a clear sign it measures nothing, so this calculator flags that case instead of answering it.
What is a good coefficient of variation?
Entirely field-dependent. Analytical chemistry often demands under 5%; biological measurements routinely run over 30% and are perfectly normal. There is no universal threshold.
Why does it break down near zero?
Because the ratio explodes as the mean approaches zero without the underlying spread changing at all. Data straddling zero is refused here for the same reason.
Is it the same as relative standard deviation?
Yes. Relative standard deviation, RSD and coefficient of variation are the same quantity, and the term used depends mostly on the field you are in.
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