Standard Error Calculator
Find the standard error of the mean from a data set.
How precise is the mean?
The standard error of the mean tells you how much a sample average is likely to bounce around the true population mean. It is the standard deviation divided by the square root of the sample size.
The larger the sample, the smaller the standard error, and the more confident you can be in the mean. It is the quantity that sets the width of a confidence interval.
Rigorous and private
The calculation runs in your browser, so your data is never uploaded.
Frequently Asked Questions
What is standard error?
The standard error of the mean estimates how much a sample mean would vary from sample to sample — the sample standard deviation divided by the square root of n.
How is it different from standard deviation?
Standard deviation measures spread of the data; standard error measures the precision of the mean estimate, and shrinks as the sample grows.
What does it feed into?
Confidence intervals and hypothesis tests about the mean.
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