On March 9 at 4:00 p.m. ET, the 2016 NFL league year officially begins. At that point, the sum of the highest paid 51 players on each team's roster has to be lower than the yet to be determined salary cap, applying the so-called Rule of 51. While we do not yet know what the 2016 salary cap will actually look like, we do know that the New England Patriots will be able to spend $1.3 million over the cap number.
Why? Because according to today's press release by the NFL Players Association, New England carries over this sum from the 2015 season (via Christopher Price):
NFLPA announces Patriots will carry over $1,347,882 in unused salary cap space from previous year.
The Patriots' number is the lowest in the AFC and the fifth-lowest in the NFL. On average, a team carried over $6.4 million from last year. For comparison, the Seattle Seahawks' number is only $11,587, while the team with the highest carryover – the Jacksonville Jaguars – will get an additional $32.8 million to work with in 2016.
Added to their existing cap space, New England now has $13.3 million to work with (via patscap.com).