Standard Deviation Calculator
Calculate population or sample standard deviation.
What this calculator does
Enter a number list to find its mean, variance, count, and population or sample standard deviation.
Inputs and what they mean
- Values
- — text value.
- Data type
- — choice value.
How to use it
- Enter the requested values.
- Choose the calculation mode when available.
- Review the result and supporting breakdown.
Formula
Standard deviation is the square root of the average squared distance from the mean; sample variance divides by n−1.
Worked example
Population deviation of 2,4,4,4,5,5,7,9
The mean is 5 and population standard deviation is 2.
Reading the result
The headline figure is the main answer. Any breakdown underneath shows the parts that make it up, so you can check the working and see what changes when you adjust an input.
Limitations and assumptions
Results depend entirely on the figures you enter and are rounded for display. They are for general information and education, not professional advice.
Common questions
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