What Is a Coefficient of Variation Calculator?
A coefficient of variation (CV) calculator measures the relative variability of a data set by dividing its standard deviation by its mean, usually expressed as a percentage. Unlike standard deviation alone, the CV lets you compare the spread of data sets that have different units or very different averages. Enter your data and the calculator returns the mean, standard deviation, and coefficient of variation.
How to Use the Calculator
- Enter your data values separated by commas or spaces.
- Calculate — see the mean, standard deviation, and CV.
The Coefficient of Variation Formula
CV = (Standard Deviation ÷ Mean) × 100%
For example, a data set with a mean of 50 and a standard deviation of 10 has a CV of (10 ÷ 50) × 100% = 20%. A lower CV means less relative variability.
Why CV Is Useful
| Measure | Tells You |
|---|---|
| Standard deviation | Spread in the data's own units |
| Coefficient of variation | Spread relative to the mean (unit-free %) |
Because the CV is unit-free, you can compare the variability of, say, heights and weights, or two investments with different average returns, on an equal footing.
Interpreting the CV
- Low CV: data is tightly clustered around the mean — more consistent.
- High CV: data is widely spread relative to the mean — more variable.
- Comparison: the data set with the lower CV is relatively more consistent.
Where CV Is Used
- Finance: comparing the risk per unit of return between investments.
- Quality control: assessing process consistency.
- Science: comparing variability across measurements with different scales.
Frequently Asked Questions
What is the coefficient of variation?
The coefficient of variation is the standard deviation divided by the mean, expressed as a percentage. It measures relative variability independent of units.
How do you calculate CV?
Divide the standard deviation by the mean and multiply by 100. A standard deviation of 6 with a mean of 30 gives a CV of 20%.
Why use CV instead of standard deviation?
CV is unit-free, so it lets you compare the variability of data sets with different units or very different means, which standard deviation alone cannot do fairly.
What is a good coefficient of variation?
It depends on context, but a lower CV indicates more consistent data. In many fields a CV under about 10%–15% is considered low variability.
Is this coefficient of variation calculator free?
Yes — it is completely free, requires no signup, and returns the mean, standard deviation, and CV.