Here is the formula, according to Over the Cap.
Methodology
App. V, §2 lays out the process of calculating the value of CFAs. §2(a) begins the calculation as follows to all players in the league
Start with the Average Per Year (APY) of the contract signed.
Subtract from the APY any money that the compensatory formula does not count3.
Rank these players by adjusted APY in descending order, and assign points to each player, equal to [number of leaguewide players]-[rank].
Add anywhere from 25 to 100 points for players who played a percentage of snaps on offense or defense in the range of 25% to 100%. (Kickers and punters are given a different point addition unrelated to snap counts.)
Add 20 or 5 points for postseason honors as determined by the AP’s All Pro list, and the PFWA’s All NFL/All Conference list.
3 Prior to the 2020 CBA, it had been determined that workout bonuses, incentives, and salary escalators were common devices that the compensatory formula does not count. However, App. V, §2(a) of the 2020 CBA makes clear that these devices will now count if they are considered Likely To Be Earned, or are earned in the player’s first season of his new contract.
Qualifying CFAs And Assigning Them To A Round
Once the Final Numerical Value (FNV) as described above has been tallied, each UFA is given a value that either assigns him as a CFA to a particular round, ranging from the 3rd to the 7th, or does not qualify him as a CFA at all. App. V, §3(b) sets these round cutoffs in a percentile manner, as follows:
RoundHighest PercentileLowest Percentile
3rd100th95th (top 5%)
4thbelow 95th (top 10%)90th (top 10%)
5thbelow 90th (top 10%)85th (top 15%)
6thbelow 85th (top 15%)75th (top 25%)
7thbelow 75th (top 25%)65th (top 35%)4
Non-CFAbelow 65th (top 35%)4lowest ranked player
4 As mentioned above, in the 2011 CBA the 7th Round/Qualification cutoff was instead at 50%. Also, prior to the 2011 CBA this cutoff may have been somewhere higher than 50%, given that fewer players were found to qualify under AdamJT13’s projections than under the 2011 CBA.