Can anyone explain why my measurements are off?
Assuming default units are meters.
I have a grid 22x22 divided into 44 rows, 44 columns, shouldn't the subdivided polys then be exactly .5 x .5 meters?
I've repeated several times using the Labs Ruler tool and the results are always larger than .5

Count the columns/rows. Columns/rows parm refers to the actual poly lines, not the space bounded by a pair of them.

Thanks.