Measure with the tape measure you have. It would be best if it is
a wide, heavy blade like a Stanley. Always try to hang some one
piece of drywall that has no outs. Put the metal end of the tape
measure against the installed sheet and measure the left and right
side of the box, get fairly accurate numbers (1/8" or less). Do
the same for the top and bottom. Layout on the new sheet. Cut
INSIDE your marks (too tight), but angle the saw way to the
outside of the cut. The back side of the rock will be way too
big, the finish side will be almost too tight. You may need to
ease the cut to fit, but it will be easy to do in the thin section
left on the finish side.
______________________________
Keep the whole world singing . . . .
DanG (remove the sevens)




"Eigenvector" wrote in message
...
I've done this several times and this is something that just
keeps eluding me.

What is the trick to measuring accurate drywall cutout holes for
outlet boxes? The big issue that I seem to have is that the
measurments need to be accurate by 1/8" all around for the job
to look professional and for the outlet plate to sit firmly.
But when I go to do it, no matter how many times I measure, I'm
always off by 1/8" which puts one side 1/4" off and another snug
against the box. I'm a firm believer in measure once cut twice
(or is that measure twice cut once...)

Are there better tools for measuring it? I'm using my tape
measure which is accurate but unwieldy and with that metal lip
on the forward edge it can be off by 1/4" if you get the tape
bowed.