What is the coefficient of variation?

The coefficient of variation (CV) is the ratio of the standard deviation to the mean, expressed as a percentage. It measures relative variability and is useful when comparing datasets with different units or scales.

When should I use population vs. sample standard deviation?

Use population standard deviation when your data represents the entire group. Use sample standard deviation (the default) when your data is a sample drawn from a larger population — this corrects for bias using n−1 in the denominator.

Can CV be calculated if the mean is zero or negative?

CV is undefined when the mean is zero (division by zero). It is mathematically valid but often misleading when the mean is negative, because the sign can distort interpretation. This calculator flags both cases.

What is a "good" coefficient of variation?

It depends on the field. In lab sciences, a CV below 5% is often considered excellent. In finance, 10–20% may be acceptable. There is no universal threshold — compare CV values within the same domain.

How is CV different from standard deviation?

Standard deviation is an absolute measure of spread in the same units as the data. CV is dimensionless and relative, making it easier to compare variability across datasets with different scales.

Coefficient of Variation Calculator

Name: Coefficient of Variation Calculator
Availability: InStock
Author: Nham Vu

Enter your dataset and instantly get the coefficient of variation (CV), mean, and standard deviation.

Enter Dataset

Numbers (comma, space, or newline separated)

Standard Deviation Type

Sample (n−1) Population (n)

Quick Examples

Enter numbers above and click Calculate

Copied!

Summary

Enter your dataset and instantly get the coefficient of variation (CV), mean, and standard deviation.

How it works

Enter your numbers separated by commas, spaces, or newlines.
The calculator computes the mean (average) of your dataset.
It then computes the standard deviation (population or sample, your choice).
CV is calculated as (standard deviation / mean) × 100%.
Results update instantly as you type.

Use cases

Compare variability of test scores across different exam formats.
Assess consistency of manufacturing measurements or lab results.
Evaluate investment risk by comparing return volatility across assets.
Determine which of two datasets has more relative spread.
Quality control: check whether a process stays within acceptable variance.
Scientific research: normalize dispersion when units differ between groups.

Frequently Asked Questions

Last updated: 2026-06-09 · Reviewed by Nham Vu