How passer rating works
NFL passer rating turns five box-score numbers — completions, attempts, yards, touchdowns and interceptions — into a single figure between 0 and 158.3. It does this by scoring four rate categories separately, capping each so no single stat runs away with the number, then averaging them onto the final scale. A rating near 158.3 is a "perfect" game, roughly 100 is very good, and the modern league average sits in the high 80s to low 90s.
The four components are:
a = ((C / A) − 0.3) × 5— completion percentageb = ((Y / A) − 3) × 0.25— yards per attemptc = (TD / A) × 20— touchdown percentaged = 2.375 − ((INT / A) × 25)— interception percentage
Each of a, b, c and d is then clamped to the
range 0 to 2.375. Finally the rating is
((a + b + c + d) / 6) × 100. The 2.375 cap on each term is what fixes the maximum at
158.3 rather than an open-ended number.
How to read the result
Passer rating is a quick snapshot, not the last word. It rewards efficiency — completion rate, yards per throw and touchdowns — and punishes interceptions heavily, but it ignores rushing, sacks, fumbles and the quality of the defense faced. For a full breakdown of the formula and its history, read how passer rating is calculated, and to see why ESPN's QBR often disagrees with it, read passer rating vs QBR.
Frequently asked questions
How is NFL passer rating calculated?
NFL passer rating combines four categories, each measured per pass attempt: completion percentage, yards per attempt, touchdown percentage and interception percentage. Each produces a component value — a = ((completions/attempts) − 0.3) × 5, b = ((yards/attempts) − 3) × 0.25, c = (touchdowns/attempts) × 20, and d = 2.375 − ((interceptions/attempts) × 25). Every component is capped to the range 0 to 2.375 so no single stat can dominate. The four are added, divided by six and multiplied by 100. The result runs from 0 to a maximum of 158.3.
What is a perfect passer rating?
A perfect passer rating is 158.3 — the highest score the formula can produce. It happens when all four components hit their 2.375 cap at once: a completion rate of at least 77.5%, at least 12.5 yards per attempt, a touchdown on at least 11.875% of attempts, and zero interceptions. Because each component is capped, a quarterback cannot push the rating past 158.3 no matter how gaudy the raw numbers get. Dozens of quarterbacks have posted a perfect 158.3 in a single game, but no one sustains it across a season.
What's a good passer rating?
As a rough guide, a rating around 90 is solid, 100 or higher is very good, and 110-plus over a full season is elite, MVP-level play. The league-average passer rating in the modern NFL sits in the high 80s to low 90s, so anything below about 78 is subpar. Context matters — a rating is inflated by a dink-and-dunk day and dragged down by drops or a couple of unlucky interceptions — but as a quick single-number snapshot of a passing line, roughly 100 is the informal 'very good' threshold.
Why is the maximum passer rating 158.3 and not 100?
The 158.3 ceiling is a quirk of the formula's history. Each of the four components maxes out at 2.375. Adding four of them gives 9.5, dividing by six gives about 1.5833, and multiplying by 100 gives 158.3. When the NFL adopted the system in 1973 it deliberately set the 'average' benchmarks of the early 1970s to produce a rating near 66.7 (a component value of 1.0 each), which left the maximum at 158.3 rather than a round 100. The scale has never been rebased, so 158.3 remains the perfect score.
Is passer rating the same as QBR?
No. Passer rating is the traditional NFL formula on this page: it uses only completions, attempts, yards, touchdowns and interceptions, and runs 0 to 158.3. ESPN's Total QBR is a separate, proprietary metric on a 0 to 100 scale that also weighs rushing, sacks, fumbles, down and distance, and adjusts for the strength of the defense — so the two can disagree sharply on the same game. Passer rating is transparent and reproducible by hand; QBR is a model you cannot recompute yourself.