Calculating a Geometric Mean with some negative values

[Marcus from Belmont]

I am trying to work out how to calculate the geometric mean of a series of values, some of which are negative, ie. investment returns over a series of years with some negatives.

The Geomean function doesn't work because it only uses positive numbers.

Any help would be greatly appreciated.

 

[Nem]

Try this

=GEOMEAN(ABS(A1:A6))