Math
Standard Deviation Calculator
Measure how spread out a list of numbers is around its mean, using the population formula.
The result is the population standard deviation, which shows how spread out the entered numbers are around their mean.
Formula
Population standard deviation = square root of the average squared distance of each value from the mean.
How it works
Type numbers separated by commas. The calculator finds the mean, averages the squared differences from it, and takes the square root.
Worked example
For example, for the numbers 4, 8, 15, 16, 23 and 42, the mean is 18, the average squared distance from the mean is 151.6667, and the square root of that average is 12.3153.
FAQs
What does the Standard Deviation do?
It takes the values you enter and works out the standard deviation for you, showing the result straight away.
What should I enter?
Enter ordinary numbers in the boxes above. If a value does not make sense for this calculation, the page will ask you to check it instead of showing a wrong answer.
Can I use the result for homework or everyday math?
Yes. It is a general-purpose math helper; for exam or professional work, still check the steps against your own working.
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