In the case where the start number in col A is -0- your formulas below
return a result of 100% which is mathematically incorrect. Dividing
by -0- can never achieve a valid result.

Thus I vote for this formula:
=IF(A1=0,"NA",IF(A10,(B1-A1)/A1,(B1-A1)/(-1*A1)))

On 25 Nov 2005 17:06:26 -0800, wrote:

I wrote:
But if you can have mixed positive and negative results, I
would also cover the case where "start" is zero, e.g:
=IF(B1 < A1, -1, 1) * IF(A1 < 0, ABS((B1-A1)/A1), 100%)
Of course, the choice of 100% is arbitrary.

The following is better, in case both A1 and B1 are zero:

=SIGN(B1-A1) * IF(A1 < 0, ABS((B1-A1)/A1), 100%)