Well it depends, most are about 12-14 inches from the wall, to the center of the hole.
My American Standard, was less than that, by about 5 inches..(Unfortunately the hole was there already, and I wasnt going to retrofit on an easter morning, so I just got it and plunked it down on the hole and had to put a 4" foam backing on the back of the toilet tank because the sucker rocked! Never heard of a toilet that didnt seat on porcelin to porcelin, no, it rests on a rubber donut!..sheesh! I got the Champion series, that takes 2 dozen golf balls in one flush, "still to be determined at a later date" ..)...
So, check with the one that you are thinking of purchasing on the net, (it should have the rough in on there), and then make it accordingly...