Standard
Deviation
Calculator

Calculate standard deviation, variance, mean, and summary statistics from a list of numbers.

Input Numbers

Sorted Values

10, 20, 30, 40, 50

Results

Population Standard Deviation

14.142136

Sample Standard Deviation

15.811388

Population Variance

200

Sample Variance

250

Mean

30

Count

5

Sum

150

Min

10

Max

50

Learn more

What does one sigma really mean, and why does the bell curve matter?

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Frequently Asked Questions

Standard deviation measures how spread out the values in a data set are relative to the mean. A low standard deviation indicates values clustered closely around the mean, while a high value indicates greater variability.

Population standard deviation divides by N (the total number of values) and is used when you have data for an entire population. Sample standard deviation divides by N minus 1 to provide an unbiased estimate when the data is a sample from a larger population.

A standard deviation of 1 means that on average, values in the data set differ from the mean by 1 unit. In a normal distribution, approximately 68% of values fall within one standard deviation of the mean.

Standard Deviation Calculator | ToolsCanvas