Math
Standard Deviation Calculator
Measure how spread out a list of numbers is around its mean, using the population formula.
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.
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 maths?
Yes. It is a general-purpose maths helper; for exam or professional work, still check the steps against your own working.