Standard Deviation Calculator
Population and sample standard deviation and variance, step by step.
What is a standard deviation calculator?
A standard deviation calculator measures how spread out a set of numbers is. It shows the population and sample standard deviation, the mean and the steps.
How to use the standard deviation calculator
Enter your numbers separated by commas, then click Calculate. The calculator shows the population SD, the sample SD and the mean.
Standard deviation formula
Population SD = √(Σ(x − mean)² ÷ N) and Sample SD = √(Σ(x − mean)² ÷ (N − 1)). The standard deviation is the square root of the variance.
Example
For 2, 4, 4, 4, 5, 5, 7, 9: Mean = 5, Population SD = 2 and Sample SD = 2.1381.
Frequently Asked Questions
What is the standard deviation of 2, 4, 4, 4, 5, 5, 7, 9?
The population standard deviation is 2 and the sample standard deviation is 2.1381. Try it on the calculator above.
What is the difference between population and sample standard deviation?
The population standard deviation divides by N, the number of values. The sample standard deviation divides by N − 1, which corrects for using a sample.
What is the mean of 2, 4, 4, 4, 5, 5, 7, 9?
The mean of 2, 4, 4, 4, 5, 5, 7, 9 is 5. Try it on the calculator above.
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