Math
Standard deviation
Calculate population mean, variance and standard deviation for five values.
Calculators / Math / Standard error of the mean
Standard error of the mean calculator
Estimate the standard error from sample standard deviation and sample size.
On this page
Standard error1.2
Calculator controls
How to calculate
Estimate the standard error from sample standard deviation and sample size.
standard error = sample standard deviation ÷ √sample size
Worked example
Sample standard deviation: 12; Sample size: 100.
Standard error: 1.2 .
Assumptions and limits
This assumes independent observations. The standard error measures uncertainty in the sample mean, not spread among individual observations.
Results are rounded for display; calculations use unrounded values. Read our calculation methodology.
Understanding the result
Estimate the standard error from sample standard deviation and sample size. The result follows the displayed formula and keeps every adjustable assumption visible.
When this tool is useful
Use this tool to plan quantities or compare scenarios before making a purchase or technical decision.
Understanding your inputs
| Input | What to enter |
|---|---|
| Sample standard deviation | Enter a number of at least 0 and no more than 1000000000000. |
| Sample size | Enter a number of at least 1 and no more than 1000000000. |
Frequently asked questions
What can change the standard error of the mean result?
This assumes independent observations. The standard error measures uncertainty in the sample mean, not spread among individual observations.
Should I round the inputs first?
No. Enter the best measurements available and round only the practical final quantity, such as full packs, boards, sheets, or components.