Coefficient of Variation Calculator
Measure relative variability by expressing the standard deviation as a percentage of the mean.
Data type
- 1
Mean
Σx ÷ 6 = 12.1667 - 2
Sum of squared deviations
Σ(x − 12.1667)² = 26.8333 - 3
Standard deviation
√(26.8333 ÷ 5) = 2.3166 - 4
Coefficient of variation
(2.3166 ÷ 12.1667) × 100 = 19.04%
How does this calculator work?
The coefficient of variation is the standard deviation divided by the mean, expressed as a percentage: CV = (s / x̄) × 100%. It measures relative variability without units, so you can compare spread across datasets of different scales. A lower CV means more consistent data; under 15% is typically low.
Formula
How this is calculated
The coefficient of variation (CV), also called relative standard deviation (RSD), gauges how spread out data is relative to its average. You can enter a list of raw values, or supply a mean and standard deviation directly. When two or more numbers are detected in the data box, those values drive the calculation and the manual mean/SD fields are ignored.
From a data list, the mean is x̄ = Σx / n. The standard deviation is s = √(Σ(x − x̄)² / d), where the divisor d is n − 1 for a sample (Bessel’s correction, the unbiased estimator) or n for a full population, selected with the data-type control. The CV is then (s / x̄) × 100%, reported both as a percentage and as the raw ratio s / x̄.
CV is unitless, so it lets you compare variability across datasets with different units or very different scales. It is only meaningful for ratio-scale data with a positive mean: if the mean is zero the CV is undefined (division by zero) and the calculator returns no result. CV can also be misleading when values can be negative or near zero. As a rough guide, the meter flags CV below 15% as low, 15–30% as moderate, and above 30% as high relative dispersion.
Frequently asked questions
It depends on context, but lower CV means more consistent data. As a general rule of thumb a CV under 15% is considered low variability, 15–30% moderate, and above 30% high.
Use the sample option (divide by n − 1) when your data is a sample drawn from a larger group, which is the most common case. Use population (divide by n) only when your values represent the entire population.
CV divides the standard deviation by the mean, so a mean of zero makes it undefined. CV is also unreliable for data that includes negative values or means close to zero.
Also known as
TG we-Calculate Editorial Team. (2026). Coefficient of Variation Calculator [Online calculator]. TG we-Calculate. https://we-calculate.com/calculator/coefficient-of-variation-calculator
TG we-Calculate Editorial Team. "Coefficient of Variation Calculator." TG we-Calculate. 2026. https://we-calculate.com/calculator/coefficient-of-variation-calculator.
TG we-Calculate Editorial Team, "Coefficient of Variation Calculator," TG we-Calculate, 2026. [Online]. Available: https://we-calculate.com/calculator/coefficient-of-variation-calculator
@misc{wecalculate_coefficient_of_variation_calculator, title = {Coefficient of Variation Calculator}, author = {{TG we-Calculate Editorial Team}}, howpublished = {\url{https://we-calculate.com/calculator/coefficient-of-variation-calculator}}, year = {2026}, note = {TG we-Calculate} }
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