Standard Error: SD = 15, n = 25
A standard deviation of 15 with sample size 25 yields a standard error of 3.0.
How to use this tool
- Enter standard deviation (s) and sample size (n) in the fields above.
- Results update instantly as you type — or click Calculate.
- Read your standard error (se) and the full breakdown beneath it.
Compute the standard error of the mean for IQ-scale data (σ = 15) with a small sample of 25 observations.
Frequently asked questions
- What is the difference between standard deviation and standard error?
- Standard deviation (SD) describes the variability of individual data points around their mean. Standard error (SE) describes the variability of the sample mean itself — it shrinks as sample size grows: SE = SD / √n.