That is very close but maybe a little off on this years hit and we would also want to consider cap savings, not just dead money. Its difficut to figure out the exact numbers due to contract structure and timing of the deal, but here is what we know for sure. The new team would assume the unpaid salary and roster bonuses for the remainder of the contract - including all unpaid guarantees. The Bills would get hit with what theyve already paid him this season plus any unaccounted for signing bonus money.
His signing bonus is being written off at $3.2M a year through 2020. That means the Bills get hit with $3.2M this season plus $9.6M next. His compensation this season is $9M ($7.5M guaranteed). We would only get hit with whatever portion of games he is on our roster for. Lastly, he has $2M in roster bonuses this season. The structure is unclear. It is probably divided evenly among all 16 games and paid only if hes on the active roster for the games, but mightve been a lump sum at the beginning of the league year.
So if we assume that Glenn would play this week, be traded next week and that the roster bonus structure is per game active, then it calculates as such:
2017 Dead: $3.375M salary + $3.2M signing bonus + $250k roster bonus = $6.825M total 2017 dead
2018 Dead: $9.6M
2017 Cap Impact: $14.2M expected cap hit - $5.625M salary assumed by new team - $1.5M roster bonuses unpaid due to inactivity or paid by new team = $7.075M revised 2017 cap hit. Thats a cap hit reduction of $7.125M this season.
This would mean that the Bills would gain $7.125M in cap space this season and get hit with $9.6M next. That $7.125M would be carried over so in effect trading Glenn next week would result in an effective cap hit of $2.475M versus where they stand today. If the roster bonus has already been completely paid wed have $1.5M more in dead cap this season and overall cap hit.
Realistically its still a lot of dead money to eat, so the trade compensation would really have to be worthwhile for the Bills to consider moving him.