How to match 4'x8' sheathing on 16"O/C studs

I am going to build a 6’x8’ shed with 16”O/C studs but I have a measuring problem . When I draw this out in sketch up I keep coming up with studs that don’t end up with the proper spacing to allow the sheathing to be nailed to them ,it keeps coming up 3/4”short so I would have to add another stud at the joint to nail the sheathing.
The only way I have found to make the seams match is to make the first stud 15 1/4” O/C and then the rest 16’ , is this normal or am I missing something?