Larger samples give smaller standard errors: quadrupling the sample size halves the SE.
How to use the Standard Error Calculator
- Data
Results update as you type, and every field accepts the units shown in its menu.
How it works
Divide the sample standard deviation by the square root of the sample size.
What each result means
- Standard error of the mean = stdev([Data])÷sqrt(count([Data]))
- Standard deviation = stdev([Data])
- Sample size = count([Data])
- Mean = mean([Data])
Formula
SE = s ÷ √nWorked example
Inputs — Data: 12.1, 11.8, 12.4, 12.0, 11.9, 12.3, 12.2.
Results — Standard error of the mean = 0.08165; Standard deviation = 0.21602; Sample size = 7; Mean = 12.1.
Frequently asked questions
Is standard error the same as standard deviation?
No; SD describes spread of data, SE describes uncertainty in the mean.
How is SE used?
To build confidence intervals and test statistics.
What formula does the Standard Error Calculator use?
SE = s ÷ √n.