According to Spotrac’s super-duper 2021 NFL Free Agents tracker, there are currently 793 players who are either already free agents (ex. J.J. Watt) or will become free agents in four weeks’ time.
That’s an average of almost 25 per team. And with half the teams in the league currently over the cap, the number of free agents will increase as teams start shedding salaries.
Update: As of 2/16, only 12 teams are over the cap. The Texans got on “the right side of the line” by releasing J.