Although the Descriptive Statistics tool in the Analysis ToolPak can generate a report that includes the standard error of the mean, there is no function in Microsoft Excel to automatically calculate this value by itself.
To calculate the standard error of the mean by itself, use the one of the following formulas
= STANDARD DEVIATION / SQUARE ROOT OF THE POPULATION SIZE
= STDEV(range of values)/SQRT(number)
The range of values is the data used to determine the standard deviation.
The number is the size of all the possible random samples.
means XL2003 XL2007 XL2010