Calculate the coefficient of variation (CV = SD / mean × 100%) to compare relative variability between datasets with different units or scales.
Share this calculator
42.76%
Coefficient of variation
2.14
Standard deviation
5
Mean
| Coefficient of variation (CV) | 42.76% |
| Standard deviation (s) | 2.14 |
| Mean (x̄) | 5 |
| Count (n) | 8 |
Also in Statistics
Descriptive Statistics
The coefficient of variation (CV) is the ratio of the standard deviation to the mean, expressed as a percentage: CV = (s / |x̄|) × 100. It measures relative variability — how large the spread is relative to the centre — enabling fair comparison of variability across datasets with different units or very different means.
Standard deviation has the same units as the data. Comparing raw SDs across datasets measured in different units (e.g. height in cm vs weight in kg) is not meaningful. CV normalises spread as a percentage of the mean, making comparisons across scales valid.
Example: Dataset A has SD = 5, mean = 50 (CV = 10%). Dataset B has SD = 2, mean = 10 (CV = 20%). Dataset B is more variable relative to its centre even though its raw SD is smaller.
Low CV (< 10–15%) generally indicates low relative variability; high CV (> 30%) indicates high relative variability. These thresholds vary by domain. In analytical chemistry, CV < 2% is expected; in ecology, CV of 50% or more may be unremarkable.
CV is only meaningful for ratio-scale data with a positive mean. It should not be used for interval-scale data (e.g. temperature in °C, where 0°C is arbitrary) or when the mean is near zero.
Frequently asked questions
CV divides SD by the mean. If the mean is zero or very close to zero, CV becomes infinite or extremely large, which conveys no useful information. This calculator returns null when the mean is zero.
This calculator uses the sample standard deviation (dividing by n − 1) as is standard for data analysis. If computing CV for a known complete population, use σ (divide by n).
There is no universal threshold — interpret CV in your domain context. Quality control may require CV < 5%. Biological research often accepts CV < 20%. Social sciences may see CV up to 50% as routine.
Related
These related calculators come from the same leaf category, nearby sibling categories, or the same top-level topic.
Calculate sample or population standard deviation, variance, mean, and summary values from a list of numbers.
Calculate sample or population variance and standard deviation from a list of numbers, with mean, count, sum, and range.
Calculate the mean absolute deviation (MAD) as a robust measure of spread — the average distance of each value from the mean.
Find the mean, median, mode, and range of any dataset. Handles multimodal and no-mode cases with count, sum, minimum, and maximum.
