What size tile hole saw for 3/4" pipe?

This may be the silly question of the day, but what size hole do you cut in the shower wall tile to accommodate 3/4" pipe (for the shower arm and the tub spout feed.)

Do you want to cut it at 3/4" tight or how big a hole do you cut to give you a little wiggle room if your measurement is off a few ticks and to have the tile not actually contact the pipe.

Thanks.
.
.