Harmonic mean function. HARMEAN(range) computes the harmonic mean of the contents of the cells in the specified range.
The argument range can be a list of numbers, cell addresses, cell ranges (such as A1:A10).
Range can also be a matrix. In that case the function returns a matrix with one row and the same number of columns, with each element the HARMEAN of the corresponding column. If range is a row matrix, it is converted to a column matrix first.
The harmonic mean is calculated as follows:
The harmonic mean is undefined for a data set that contains zero or negative values.