A simple calculation - if it were not for negative values

Hi everyone,

I'm stumped on what should be a simple calcuilation and would welcome your help.

I have a GP figure for This Year (TY) and Last Year (LY). The variance is simple TY / LY = %Variance

However if you have a negative figure of -10% for TY and  LY is 30, the % variance reports a negative variance which is correct.

Reverse this scenario with 30 TY and -10 LY and the variance is still negative.

I need to build some error handling to allow for negative values in TY or LY or TY & LY into the formula but wondered am I missing something before I reinvented the wheel?

With thanks,

Gill