who gets to wear what numbers

So my wife asked me how they determine the numbers players wear in football.  I came across this handy chart to help explain it all.

Each NFL team consists of 53 players, although only 45 players can dress up per game.

So let's go through an example.  NFL teams normally carry 3 quarterbacks on their rosters, meaning they don't need to have a lot of numbers made available, but those quarterbacks have to pick from the same set of numbers that K (Kickers) and P (Punters) have to pick from.  So it is five position players get their pick of the numbers from 1-19.

Sometimes there can be an issue where NFL teams have retired numbers that are no longer available for players to wear.  The Chicago Bears have retired numbers 51 and 56, meaning they may not have enough numbers for all their LB (linebackers) during certain seasons.

In rare instances, the NFL will allow players to wear numbers outside of the range assigned for the player.