Mean, Median, Mode Calculator
Mean, median, mode, range.
Open →
Math
Standard Error Calculator
Enter the standard deviation and sample size to get the standard error of the mean.
Standard error
—
SE of the mean.
| √n | — |
|---|---|
| 95% margin of error | — |
| Std deviation | — |
| Sample size | — |
Show our math
Enter your figures above to see the step-by-step working.
Everything computed client-sideEverything computed client-side — nothing leaves this page
How the Standard Error Calculator Works
The standard error of the mean measures how much a sample’s average is likely to vary from the true population mean. It’s the standard deviation divided by the square root of the sample size — so bigger samples give smaller standard errors and more precise estimates. This calculator also shows the 95% margin of error, which is about 1.96 standard errors.
Don’t confuse it with standard deviation: standard deviation describes the spread of individual values, while standard error describes the precision of the mean. Quadrupling the sample size halves the standard error.
standard error = standard deviation ÷ √sample size
Frequently Asked Questions
What is standard error?
A measure of how precisely a sample mean estimates the true mean. It shrinks as the sample grows.
How is standard error different from standard deviation?
Standard deviation measures spread among individual data points; standard error measures the variability of the sample mean.
How do I reduce standard error?
Increase the sample size. Because it divides by the square root of n, four times the data halves the standard error.
More From The Desk
Same plain method, different figuresPercentile Calculator
Percentiles & quartiles.
Open →Z-Score Calculator
Standard score.
Open →Combination & Permutation Calculator
nCr and nPr.
Open →