TimelyScholarFree Tools › Standard Error to Standard Deviation Converter
Convert a standard error, or a confidence interval for a mean or a mean difference, into the standard deviation you need for meta-analysis. Also converts SD to SE.
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| Standard deviation (SD) | 8.485 |
|---|---|
| Method | SD = SE × √n = 1.200 × √50 |
Use the SE of a single group's mean, not the SE of a difference between groups (for that, use the mean-difference option).
SE → SD, SD → SE, or CI → SD.
And the sample size of each group.
Enter it into your meta-analysis software.
The standard deviation describes how much individual values vary. The standard error describes how precisely the mean is estimated, and shrinks as the sample grows: SE = SD/√n.
Meta-analyses of means need SDs, but studies often report SEs or confidence intervals instead. For a confidence interval from a small sample, the t distribution should be used rather than 1.96.
Divide the width of the interval by 3.92 (or by 2 × the t value for small samples) to get the SE, then multiply by √n.
Not with SE → SD. Use the mean-difference option, which assumes both groups have the same SD.