My WAG here would be:
25 Offensive players (11 starters with backups)
25 Defensive players (11 starters with backups)
3 Special teams players (Kicker, Punter, Long snapper)
I’m hoping for someone with actual NFL coaching experience to enlighten me. 
Moving to The Game Room from GQ.
Colibri
General Questions Moderator
There is no one set way. Some teams carry 3 QBs, some only 2. Some carry 8 offensive linemen, some 10, and so on.
Not a coach, just a football fan.
In general, the split is going to, indeed, be roughly half offense, half defense, though the specific details are going to vary by team and coaching philosophy. Also, there are some positions where a team will carry multiple backups – most teams will have 3 quarterbacks on their active roster, 3-4 halfbacks, and as many as 5 or 6 wide receivers, while they may not carry 10 active offensive linemen.
Another factor is special teams, and the “regular” position that’s played by players who predominantly play on special teams (such as returners).
Here’s what the current active roster looks like for the Packers (my favorite team):
Quarterback: 2
Halfback (now commonly just referred to as “running back”): 3
Fullback: 3
Wide Receiver: 5
Tight End: 3 (though one is a TE/LB)
Tackle: 3
Guard: 4
Center: 2
Defensive End: 4
Nose Tackle (the Pack now plays the 3-4): 2
Linebacker: 9
Cornerback: 6
Safety: 4
Kicker: 1
Punter: 1
Long Snapper: 1
That’s a good example of how different teams do things different ways. Does anyone else carry three fullbacks? Seems really high. My Bears, for example, only have one.
Yup, that’s a high number, even for the Packers, who’ve traditionally carried two. Korey Hall (the starter) and John Kuhn (second-string) both play quite a bit on offense. The Pack will occasionally use a full-house backfield, with both Hall and Kuhn as blocking backs, with a single running back lined up behind them. I’d never heard of Quinn Johnson (third-string) until I looked up their roster last night for my earlier post; I’m guessing he plays almost exclusively on special teams.
But, yeah, a lot of teams have a single fullback on their roster, or none at all, depending on the type of offense they run (some teams use a tight end as an “H-back” to fill that run-blocking role).