GWN Tools · Calculators

Standard Deviation Calculator

Paste a list of numbers (separated by commas, spaces, or new lines) to get the mean, the population and sample standard deviation, and the variance.

2
population standard deviation (n = 8)
Mean (μ)
5
Sample SD
2.1381
Population variance
4
Sample variance
4.5714

Results update as you type. Sample statistics need at least 2 values.

About the standard deviation calculator

How do you calculate standard deviation?

Find the mean of the numbers, subtract the mean from each value and square the result, average those squared differences to get the variance, then take the square root. Population standard deviation divides by n; sample standard deviation divides by n − 1.

What is the difference between population and sample standard deviation?

Population standard deviation divides the sum of squared differences by n and is used when your data is the entire group. Sample standard deviation divides by n − 1 and is used when your data is a sample drawn from a larger population, which makes it slightly larger.

What is variance?

Variance is the average of the squared differences from the mean. Standard deviation is simply the square root of the variance, expressed in the same units as the original data.