Coefficient of Variation (CV) Calculator

The CV is the standard deviation divided by the mean. It expresses spread relative to the average, usually shown as a percentage, and it has no units. A CV of 0.427618 means the standard deviation is about 42.76% of the mean.

Because it is unitless, the CV lets you compare variability across data sets with different units or very different averages, which a raw standard deviation cannot. A 10 kg spread means one thing on 50 kg loads and another on 5000 kg loads, but the CV captures both on the same scale.

Type or paste them into the Data set box separated by commas, spaces or new lines. The parser splits on any run of those characters, so a messy paste from a spreadsheet or a plain comma list both work.

Use the sample CV, the default, when your data is a sample drawn from a larger group. Use the population CV when your data covers the entire group. Sample divides the squared deviations by n minus 1, population divides by n, so the sample figure is slightly larger.

The sample standard deviation divides by n minus 1, and with a single value that denominator is zero, which is undefined. The population option divides by n and will work on one value, though the spread of a single point is always zero.

The CV divides the standard deviation by the mean, so when the mean is zero that division is undefined and the tool reports an error. This also makes the CV unreliable for data centered near zero, where a tiny mean inflates the ratio.

For all-positive data it is non-negative. If the mean is negative the ratio comes out negative, so in practice the absolute value is used when interpreting spread. The CV is most meaningful for data measured on a ratio scale with a true zero.

The engine rounds each figure to six decimal places, and the percentage is shown to four decimals. That is more than enough precision for reporting, and it avoids the long trailing digits that floating-point arithmetic would otherwise produce.

Yes. The calculation runs entirely in your browser, so your numbers never leave your device and nothing is uploaded to a server.