How to Use the Coefficient of Variation Calculator
When you want to compare the relative variability of two data sets with different average sizes, the coefficient of variation (CV) is the right tool. Standard deviation alone is affected by the units and scale of the data, but CV divides standard deviation by the mean to express variability as a relative ratio, making it possible to fairly compare data sets of very different magnitudes.
This calculator takes a list of numbers and automatically computes the mean, standard deviation, and CV (%). If your data represents the entire population, choose population mode (÷n); if it's a subset, choose sample mode (÷n-1).
For example, if two classes have average test scores of 80 and 40 respectively, comparing their CVs tells you which class's scores were relatively more evenly distributed. CV is widely used in quality control, comparing investment risk, and analyzing experimental data.
Frequently Asked Questions
It's the standard deviation divided by the mean, used to compare relative variability between data sets with different average sizes.
Population standard deviation divides by n, while sample standard deviation divides by n-1. Use sample mode if your data is a subset of a larger population.
Since CV is the standard deviation divided by the mean, it can't be calculated when the mean is 0.