Coefficient of Variation Calculator
Compare standard deviation with the absolute mean to express relative variability as a percentage.
Privacy: calculator inputs are processed in your browser; Lynara does not need to upload these values to calculate the result.
Formula
CV = standard deviation ÷ |mean| × 100%
Relative spread needs a meaningful zero
- For a suitable ratio-scale measurement with mean 50 and population standard deviation 5, CV is 10%.
- Multiplying every observation by 100 multiplies both mean and standard deviation by 100 and leaves CV unchanged. Adding an arbitrary constant does not preserve that ratio.
What the result tells you
This can compare relative spread for suitable positive ratio-scale quantities. A numerically computable ratio is not interpretable for every measurement scale.
Before you use the result
A zero or near-zero mean makes the ratio undefined or unstable. Celsius temperatures, arbitrary score origins and negative values require care; using the absolute mean does not resolve those limitations.
References for this method
Useful for
- Relative variability comparisons
- Statistics coursework
- Comparing spread across scales
Questions
Why is CV undefined when the mean is zero?
The formula divides standard deviation by the magnitude of the mean, so a zero mean makes the ratio undefined.
Should I use sample or population CV?
Use the standard-deviation convention required by your data context; the calculator shows both when sample SD is defined.