Coefficient of Variation Calculator
Calculate the relative variability (dispersion) of your data, expressed as a percentage.
What is Coefficient of Variation?
The coefficient of variation (CV) is a standardized measure of dispersion that expresses the standard deviation as a percentage of the mean. It's particularly useful when comparing the variability of datasets with different units or vastly different means.
Formula
CV = (s / |M|) × 100%
Where s = sample standard deviation and |M| = absolute value of the mean
Interpretation Guidelines
- CV < 15%: Low variability - data points are relatively consistent
- CV 15-30%: Moderate variability - reasonable dispersion around the mean
- CV > 30%: High variability - data points are widely spread
Common Use Cases
- Comparing consistency: Compare variability across datasets with different units (e.g., height in cm vs weight in kg)
- Quality control: Assess the reliability and consistency of manufacturing processes
- Investment analysis: Compare risk relative to expected return across different investments
- Method comparison: Evaluate which measurement technique produces more consistent results
- Assessing reliability: Determine if measurement instruments produce consistent readings
When to Use
Use the coefficient of variation when you want to compare variability across:
- Datasets with different measurement units
- Variables with vastly different means
- Multiple groups or conditions
Note: CV is only meaningful for ratio-scale data (where zero indicates absence of the quantity). It should not be used with interval data (like temperature in Celsius) or when the mean is close to zero. This calculator divides by the absolute value of the mean, so negative means are reported as positive relative variability.
