Football Passer Rating Calculator
One Number Built From Four Deliberately Capped Pieces
The NFL passer rating has a reputation for being confusing, and the reputation is earned — it is not one calculation but four, each built from a different passing stat, each individually capped, then averaged together and scaled onto a 0-to-158.3 range. The cap is what trips people up: a quarterback can throw for enormous yardage or an absurd touchdown rate and still not move the needle past a certain point, because each component maxes out on its own before the four are combined. This calculator runs the full official formula, component by component, rather than a rounded approximation of it.
The Formula
Each of the four components is calculated from a passing stat divided by attempts, then clamped between 0 and 2.375 before averaging:
b = ((Yards / Attempts) − 3) × 0.25
c = (Touchdowns / Attempts) × 20
d = 2.375 − ((Interceptions / Attempts) × 25)
Each of a, b, c, d is clamped to a minimum of 0 and a maximum of 2.375
Passer Rating = ((a + b + c + d) / 6) × 100
The clamp on each component is what keeps the scale bounded: since every component tops out at 2.375, the highest possible rating is (2.375 × 4 / 6) × 100 = 158.3, regardless of how gaudy the underlying stat line gets.
Where This Number Gets Used
- Single-game evaluation — broadcasters and box scores post a passer rating for every quarterback after every game as a quick, if incomplete, efficiency summary.
- Season and career comparisons — because the formula is standardized, it lets fans and analysts compare quarterbacks across different eras and offensive systems on a common scale.
- Contract and award discussion — passer rating regularly comes up in MVP and contract-value arguments alongside counting stats like total yards and touchdowns.
- Understanding its limits — the formula ignores rushing production, sacks, and drops, which is exactly why running the numbers yourself clarifies what the rating is, and isn't, measuring for a given game.
Component Behavior at a Glance
| Game line (Cmp/Att, Yds, TD, INT) | a | b | c | d | Rating |
|---|---|---|---|---|---|
| 24/35, 315 yds, 3 TD, 1 INT | 1.929 | 1.500 | 1.714 | 1.661 | 113.4 |
| 20/33, 220 yds, 1 TD, 1 INT | 1.530 | 0.917 | 0.606 | 1.617 | 77.8 |
| 24/24, 400 yds, 10 TD, 0 INT (perfect line) | 2.375 | 2.375 | 2.375 | 2.375 | 158.3 |
Figures computed directly from the formula above. The third row shows why 158.3 is the mathematical ceiling — every component is already clamped at its maximum.
How to Use This Calculator
- Enter Completions for the game or season being evaluated.
- Enter total pass Attempts.
- Enter total passing Yards.
- Enter passing Touchdowns.
- Enter Interceptions thrown.
- Select Calculate to get the passer rating along with each of the four underlying components.
Related Calculations
For a broader efficiency view that folds in additional passing context, see the Football Passing Efficiency Calculator. Fantasy managers translating the same box score into league points can use the Fantasy Football Score Calculator.