Passer Rating Explained

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Passer rating is the NFL’s official quarterback statistic — the number that shows up in every box score, on every broadcast graphic, and next to “158.3” whenever someone has a perfect game. It has been the league’s standard since 1973, and it remains the most-cited single measure of passing efficiency even though nearly everyone agrees it’s imperfect. Understanding what it actually measures explains both why it’s still around and why analysts keep building alternatives.

The formula combines four things and nothing else: completion percentage, yards per attempt, touchdown percentage, and interception percentage. It ignores sacks, rushing, fumbles, drops, game situation, and opponent. Each of the four components is scaled so that an “average” 1970s performance scored 1.0 and an outstanding one scored 2.375, then the four are added, divided by six, and multiplied by 100 — which is how the maximum lands on the famous 158.3.

The chart below walks through the exact formula, what a good rating looks like today, and how passer rating compares with QBR and other modern metrics. Take a look, then we’ll get into what it misses.

NFL STATS
Passer Rating, Explained
The formula, the scale, and what 158.3 really means
MAX
158.3
Perfect game
AVERAGE (1973)
66.7
By design
AVERAGE (2020s)
~92
Passing has exploded
INPUTS
4
Comp %, Y/A, TD %, INT %
The formula
Four components, each capped between 0 and 2.375
Component Formula Cap
a — Completions ((Comp / Att) – 0.3) x 5 0 to 2.375
b — Yards ((Yds / Att) – 3) x 0.25 0 to 2.375
c — Touchdowns (TD / Att) x 20 0 to 2.375
d — Interceptions 2.375 – ((INT / Att) x 25) 0 to 2.375
Passer rating ((a + b + c + d) / 6) x 100 0 to 158.3
Adopted by the NFL in 1973; the NCAA uses a different, uncapped formula that can exceed 200.
Reading the scale
Benchmarks for a modern quarterback
Rating What it means today
158.3 Perfect game — requires at least 77.5% completions, 12.5 yds/att, 11.875% TD rate, and zero interceptions
110+ Elite season; MVP territory (Aaron Rodgers holds the single-season record at 122.5, 2011)
100-109 Top-5 to top-10 quarterback
90-99 Solid starter — roughly the modern league average sits in the low 90s
80-89 Below average; a rating in the 80s was average in the 1990s
Under 70 Replacement level; likely losing the job
39.6 Perfectly average by the 1973 design; 0.0 is the floor (Ryan Leaf, 1998)
Passer rating vs. modern metrics
Where it fits
Metric What it adds beyond passer rating
ESPN QBR (0-100) Includes rushing, sacks, fumbles, penalties, and situational value (down, distance, score, clock); opponent-adjusted
Adjusted Net Yards per Attempt (ANY/A) Adds sacks and weights TDs (+20 yds) and INTs (-45 yds); a cleaner efficiency stat
EPA per play Expected points added — measures how much each play changed the team’s scoring outlook
Completion % over expected (CPOE) Accounts for throw difficulty using tracking data
Passer rating Simple, official, computable from a box score, comparable across 50 years — but blind to sacks, rushing, and context
PASSER RATING FACTS
Why 158.3?
Each of four components maxes at 2.375; 4 x 2.375 = 9.5; 9.5 / 6 x 100 = 158.3. The odd number is a byproduct of the scaling, not a target.
Grade inflation is real
Rules changes and offensive evolution mean a 90 rating today is roughly what a 75 was in 1980 — always compare within an era.
Not the same as QBR
ESPN’s Total QBR is a separate 0-100 model built in 2011; a quarterback can have a great passer rating and a mediocre QBR, or vice versa.

What Passer Rating Misses

Because the formula only sees pass attempts, a sack — a negative play the quarterback often owns — counts for nothing. Neither does a 40-yard scramble for a first down, a lost fumble on a strip-sack, or a spike to stop the clock (which counts as an incompletion and hurts). Context is absent too: a 5-yard completion on third-and-12 helps the rating as much as one on third-and-4, and garbage-time stats against a prevent defense count the same as fourth-quarter comebacks. That’s why analysts lean on QBR, EPA, and ANY/A when they want to compare quarterbacks — and why passer rating still shows up on every broadcast: it’s simple, it’s official, and every fan can compute it from a stat line.

The Bottom Line

Passer rating measures four things — completion rate, yards per attempt, touchdown rate, and interception rate — on a 0-to-158.3 scale that’s been the NFL’s official standard since 1973. It’s a fair snapshot of passing efficiency and a poor measure of total quarterback play, which is why it’s best read alongside modern metrics. For the model ESPN built to fix its gaps, see our guide to what QBR is, and for another 50-year-old NFL formula that still governs the calendar, how the NFL schedule formula works.