Standard Error of the Mean Calculator
Enter the sample standard deviation and sample size to calculate the standard error of the mean.
Standard Error of the Mean Calculator
Calculate the standard error of the mean — how much a sample mean is expected to vary from the true population mean.
This calculator provides an estimate for general informational purposes only. It is not a substitute for professional financial, mechanical or engineering advice.
Standard error estimates how much a sample's mean would vary from sample to sample, calculated by dividing the standard deviation by the square root of the sample size.
Example
- With the default values shown above, this calculator returns: Standard Error of the Mean ≈ 1.50.
Frequently Asked Questions
What is the formula?
Standard Error = Standard Deviation ÷ √Sample Size.
How is this different from standard deviation?
Standard deviation measures spread within a single sample's data points; standard error measures how much the sample MEAN itself would vary if you repeated the sampling — it shrinks as sample size grows, while standard deviation doesn't.