Are studs 16 inches on center?
Simply so, what is the distance between 16 on center studs?
When a home is framed, the wall studs are usually spaced 16 or 24 inches apart. If you start in a corner and measure out 16 inches and you don't find a stud, you should find one at 24 inches.
Moreover, how do you find the center of a stud?
Once you find a stud, I recommend using a nail or small drill bit to locate the center of the stud. Tap a nail halfway into the drywall and if you can't push it in, you're on the stud. Move 1/4″ to the left and right until you are able to push the nail through without contacting a stud.
If you use stack framing for your trusses and wall studs, then it helps a lot to use the same spacing on your floor joists, so your wall studs can line up exactly with the floor joists. You can probably find in somewhere in the code that you can use 16, 19.2 (you said 19-6)or 24 inch spacing legally.