How to use the nfl passer rating calculator
- Enter the quarterback's pass attempts and completions.
- Enter passing yards, touchdown passes and interceptions.
- Read the passer rating on the NFL scale and the four values that go into it.
- If one component hit its limit, a note explains it. A perfect rating is 158.3.
Formula
a = (completions / attempts - 0.3) x 5
b = (yards / attempts - 3) x 0.25
c = touchdowns / attempts x 20
d = 2.375 - interceptions / attempts x 25
Rating = (a + b + c + d) / 6 x 100, with each of a, b, c and d kept between 0 and 2.375
Each part is limited to a minimum of 0 and a maximum of 2.375, and the maximum rating is 158.3. A rating of 100 is often described as a very good game, and 39.6 is the figure for a quarterback who throws every pass to the ground, but those are just reference points.
Worked example
A quarterback goes 24 of 35 for 280 yards, 2 touchdowns and 1 interception. Then a = (0.6857 - 0.3) x 5 = 1.9286, b = (8 - 3) x 0.25 = 1.25, c = 2 / 35 x 20 = 1.1429 and d = 2.375 - 1 / 35 x 25 = 1.6607.
The sum is 5.9821, divided by 6 and multiplied by 100 gives 99.7.
A game of 10 for 10 with 300 yards and 3 touchdowns and no interceptions pushes every part to the limit, so the rating is the perfect 158.3. The other end is 4.2 for 10 of 30 with 100 yards, no touchdowns and 5 interceptions.
What the four parts measure
Completion percentage rewards accuracy, yards per attempt rewards moving the ball, touchdown percentage rewards scoring and the interception term penalizes turnovers. Each one is turned into a number between 0 and 2.375, so no single stat can run away with the rating.
The limits explain why a perfect game is not as rare in short games as in full seasons, and why a very big day cannot score above 158.3. They also explain why the rating can be the same for two very different stat lines.
How to use the number
Passer rating is a long established formula, and it has well known limits.
- It ignores sacks, rushing, fumbles, down and distance and the quality of the opponent.
- It can compare games or seasons of the same quarterback fairly well. Comparing players across eras is harder because rules and scoring have changed.
- Different leagues and levels use other formulas. This calculator uses the NFL formula.
- Other measures, such as total QBR, try to include more of the game, but they use different inputs.
Assumptions and limits
- The calculation uses the NFL passer rating formula and its limit of 2.375 on each of the four parts.
- Completions, touchdowns and interceptions must be whole numbers and cannot exceed attempts. Touchdown passes cannot exceed completions.
- Yards may be negative for a game with a few short throws and big losses, though that is rare.
- College football, the CFL and total QBR use other formulas and are not calculated here.
Frequently asked questions
How is NFL passer rating calculated?
Four parts based on completion percentage, yards per attempt, touchdown percentage and interception percentage, each limited to between 0 and 2.375. Add them, divide by 6 and multiply by 100.
What is a perfect passer rating?
The perfect rating is 158.3. It requires at least 77.5 percent completions, 12.5 yards per attempt, a touchdown on 11.9 percent of attempts and no interceptions, with each part at its limit.
Can passer rating be negative?
No. Because each part is limited to a minimum of 0, the lowest rating is 0.
Is a rating of 100 good?
It is often treated as a strong game or season. Treat it as a reference point and compare it with the league's typical rating in the same year, because the average has risen over time.