Standard Deviation Calculator
Measure how spread out a set of numbers is. Enter your values separated by commas, spaces or new lines and the calculator returns both the population and sample standard deviation, along with the variance, the mean and the count. The difference matters: use the population version when your list is the entire group, and the sample version (which divides by n minus one) when your data is a sample drawn from a larger population. A larger standard deviation means the values are more scattered around the mean, while a small one means they cluster tightly. This is a core statistic for science, finance, quality control and grading. The math is exact and runs entirely in your browser, so your data stays private.
How to use Standard Deviation Calculator
- Enter your numbers separated by commas or spaces.
- Read the mean and count.
- Compare population and sample standard deviation.
- Check the variance for the same data.
Frequently asked questions
What is the difference between population and sample standard deviation?
Population uses N in the denominator and applies when you have every data point. Sample uses N minus 1 and applies when your data is a sample of a larger group.
How is variance related to standard deviation?
Variance is the average squared deviation from the mean, and the standard deviation is simply its square root.
What does a higher standard deviation mean?
A larger value means the numbers are more spread out from the mean, while a small value means they cluster tightly around it.
What is Standard Deviation Calculator?
Measure how spread out a set of numbers is. Enter your values separated by commas, spaces or new lines and the calculator returns both the population and sample standard deviation, along with the variance, the mean and the count.
Is Standard Deviation Calculator free to use?
Yes. Standard Deviation Calculator is completely free, with no sign-up and no usage limits.
Does Standard Deviation Calculator work in a web browser?
Yes. Standard Deviation Calculator runs in any modern web browser. There is nothing to download or install.
Is my data private with Standard Deviation Calculator?
Yes. Standard Deviation Calculator runs entirely on your device in your browser, so nothing you enter is uploaded to a server.
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