This guide will detail how to calculated the relative standard deviation [%RSD] using Excel, then walk through a worked example and finally detail the limitations of the calculation. Percentage relative standard deviation is a widely used statistical tool but strangely there is no automated function in any version of Microsoft Excel.
Relative Standard Deviation in Excel 2003, 2007 & 2010
%RSD is a powerful tool to statistically inspect the variation in sets of data but a specific function is not available in Excel 2003, 2007 or even 2010. To calculate the %RSD in Microsoft Excel a short formula must be used:
= [STDEV[Data Range] / AVERAGE[Data Range]]*100
= [STDEV[A1:A11] / AVERAGE[A1:A11]]*100
The above %RSD example has been entered into the Excel formula bar and will calculate the percent relative standard deviation of the 5 value data set E6 to E11. In the cell where the formula is written a value between 0-100 will be reported. The result is expressed as an percentage, with a low number [