How the Passer Rating Works

The passer rating is a standardized measure in American football that summarizes a quarterback's passing efficiency. It combines completion percentage, yards per attempt, touchdown rate, and interception rate into one value that ranges from 0 to 158.3 in the National Football League. A higher number indicates greater efficiency. Each component is scaled so that average performance yields a rating around 85 to 90. This calculator follows the official NFL formula, clamping interim values between 0 and 2.375 before combining them. By entering your game stats, you can quickly gauge how effectively a quarterback moved the ball through the air.

Step-by-Step Formula

To compute the rating, divide completions by attempts to get accuracy. Subtract 0.3 from this figure, multiply by 5, and limit the result to the 0–2.375 range. Repeat similar steps for yards per attempt, touchdown percentage, and interception percentage, each with its own scaling factor. Add the four adjusted numbers together, divide by 6, and multiply by 100. Mathematically, each component influences the total equally, so missing the mark in one area can drag down the entire rating. Conversely, excelling in touchdowns or minimizing interceptions can dramatically improve the final figure.

Why Rating Matters

Teams often rely on passer rating to compare quarterbacks across seasons or evaluate potential trades and draft picks. While not a perfect measure—since it ignores rushing and situational context—it offers a quick snapshot of passing productivity. Coaches might use it to spot trends, like a dip in yards per attempt or a spike in interceptions, and adjust strategy. Fantasy football players also look at ratings to project future success. A consistent upward trajectory may indicate a quarterback who has matured within the offensive system.

Historical Perspective

Passer rating was introduced in 1973 to standardize quarterback evaluation. Prior to that, statistics like completion percentage or total yards were used independently, making it difficult to compare players with different playing styles. The league aimed for a formula that would place the record-setting performances of legends like Johnny Unitas and Bart Starr on a level playing field with modern athletes. By carefully selecting the constants in the formula, they ensured the best seasons approached 150, leaving room for future players to excel without the scale feeling too small.

Limitations

No single number can capture every nuance of quarterback play. Some criticisms of the passer rating include its disregard for rushing contributions and its equal weighting of touchdowns and interceptions, which might not align with a team's philosophy. Additionally, situational factors such as weather, injuries, and strength of competition can skew results. Many analysts complement the passer rating with advanced metrics like Expected Points Added (EPA) or Completion Percentage over Expectation (CPOE) for a fuller picture.

Practice with Sample Stats

Try entering famous stat lines from past seasons or your own local league data. For instance, if a quarterback completes 25 of 35 passes for 280 yards, 3 touchdowns, and 1 interception, the calculator shows how close that performance is to elite levels. You can experiment by increasing yards or reducing interceptions to see how sensitive the formula is to each factor. Over time, you'll develop intuition about what numbers constitute a good or great outing.

Formula in MathML

Below is the core formula in MathML. The components $a$, $b$, $c$, and $d$ represent the scaled metrics. Values are bounded between 0 and 2.375 before summation.

$\mathrm{Rating}=\mathrm{\backslash frac\{(a+b+c+d)\}\{6\}\backslash times100}$

Component	Formula
a	((Comp/Att) - 0.3) × 5
b	((Yards/Att) - 3) × 0.25
c	(TDs/Att) × 20
d	2.375 - (INTs/Att × 25)

Beyond the Basics

Passer rating does not account for quarterback rushing ability or leadership qualities, but it remains entrenched in record books and broadcast graphics. Analysts sometimes compare ratings across eras to gauge how offensive philosophies have changed. Over the last decade, for example, more pass-friendly rules and schemes have pushed average ratings upward. By measuring your team's quarterback each week, you can follow that broader trend within your own league.

Whether you're a coach, player, or fan, this calculator provides immediate feedback on game performance. By entering real or hypothetical stats, you can explore how each decision—throwing deep, avoiding interceptions, or pushing for touchdowns—affects the bottom line. It may also inspire deeper research into advanced analytics or spark lively debates among friends about which quarterback truly deserves the MVP trophy.