# Coefficient of Variation Calculator

Free coefficient of variation (CV) calculator. Compare relative variability between datasets with different units or means.

## What this calculates

Calculate the coefficient of variation (CV) to measure relative variability. Useful for comparing the spread of datasets with different units or magnitudes.

## Inputs

- **Standard Deviation (σ or s)** — min 0 — The standard deviation of the data.
- **Mean (μ or x̄)** — The mean (average) of the data. Must not be zero.
- **Comparison: Std Dev 2 (optional)** — min 0 — Standard deviation of a second data set for comparison.
- **Comparison: Mean 2 (optional)** — Mean of a second data set for comparison.

## Outputs

- **Coefficient of Variation (CV)** — formatted as percentage — CV = (σ / μ) × 100%.
- **CV (Decimal)** — Coefficient of variation as a decimal.
- **CV of Dataset 2** — formatted as percentage — CV for the second data set (if provided).
- **Comparison** — formatted as text — Which data set is more variable relative to its mean.

## Details

The coefficient of variation (CV) is a standardized measure of dispersion.

Formula:
CV = (σ / μ) × 100%

Why Use CV?

- Compare variability between datasets with different units (e.g., height in cm vs. weight in kg)

- Compare variability between datasets with different means

Interpretation

- CV < 15%: Low variability

- CV 15-30%: Moderate variability

- CV > 30%: High variability

Note: CV is only meaningful for ratio-scale data (data with a true zero point). It is not meaningful for interval-scale data like temperature in Celsius.

## Frequently Asked Questions

**Q: When should I use CV instead of standard deviation?**

A: Use CV when comparing variability between datasets with different units or very different means. For example, comparing the variability of heights (in cm) vs. weights (in kg). Standard deviation alone would be misleading because it depends on the scale of the data.

**Q: Can CV be greater than 100%?**

A: Yes. A CV greater than 100% means the standard deviation is larger than the mean, indicating very high variability. This can happen with highly skewed data or data with many values near zero.

**Q: Why must the mean not be zero?**

A: CV is calculated by dividing by the mean. If the mean is zero, the calculation is undefined (division by zero). CV is also not meaningful for data that can take negative values or for interval scales, since it assumes a meaningful zero point.

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Source: https://vastcalc.com/calculators/statistics/coefficient-of-variation
Category: Statistics
Last updated: 2026-04-21