Relative standard deviation

In probability theory and statistics, the relative standard deviation (RSD or %RSD) is the absolute value of the coefficient of variation. It is often expressed as a percentage. A similar term that is sometimes used is the relative variance which is the square of the coefficient of variation. Also, the relative standard error is a measure of a statistical estimate's reliability obtained by dividing the standard error by the estimate; then multiplied by 100 to be expressed as a percentage.

The relative standard deviation is widely used in analytical chemistry to express the precision and repeatability of an assay.


 * 100 &times; [(standard deviation of array X)/ (average of array X)] = relative standard deviation expressed as a percentage