How Is Qbr Calculated

Calculate the official NFL passer rating (QBR) using the standard formula. Enter your passing statistics below to see how your performance stacks up against the best quarterbacks in history.

How Is Quarterback Rating (QBR) Calculated? The Complete Guide

The NFL Quarterback Rating (QBR), also known as the passer rating, is the standard measure of a quarterback’s passing performance. Developed by the NFL in 1973, this formula evaluates four key passing statistics to produce a single number that ranges from 0 to 158.3, with higher values indicating better performance.

The Official NFL Passer Rating Formula

The quarterback rating is calculated using four components, each with a maximum value of 2.375:

1. Completion Percentage (CMP%): (Completions/Attempts – 0.3) × 5
2. Yards Per Attempt (YPA): (Yards/Attempts – 3) × 0.25
3. Touchdown Percentage (TD%): (Touchdowns/Attempts) × 20
4. Interception Percentage (INT%): 2.375 – (Interceptions/Attempts × 25)

The final rating is calculated by:

1. Calculating each of the four components
2. Ensuring no component is greater than 2.375 or less than 0
3. Summing all four components
4. Dividing by 6
5. Multiplying by 100

Why the Maximum Rating is 158.3

The perfect passer rating of 158.3 is achieved when a quarterback meets all these criteria in a single game:

• Completion percentage of at least 77.5%
• Average of at least 12.5 yards per attempt
• Touchdown percentage of at least 11.875%
• 0 interceptions

In NFL history, only a handful of quarterbacks have achieved this perfect rating in a game, including Peyton Manning (4 times), Ben Roethlisberger, and Kurt Warner.

Historical Context and Evolution

The passer rating formula was introduced in 1973 to provide a standardized way to evaluate quarterback performance. Before this, comparisons between quarterbacks from different eras were difficult due to varying offensive systems and rule changes.

Over the years, the formula has remained unchanged, though it has faced criticism for:

• Not accounting for sacks or rushing yards
• Treating all yards equally (a 5-yard completion counts the same as a 50-yard completion)
• Not considering game situations or strength of opposition
• Being more favorable to quarterbacks with high completion percentages

How QBR Compares to Other Quarterback Metrics

Metric	What It Measures	Range	Advantages	Limitations
Passer Rating (QBR)	Passing efficiency using 4 components	0-158.3	Standardized, easy to understand, historical consistency	Ignores sacks, rushing, game context
Total QBR (ESPN)	Overall quarterback contribution	0-100	Includes all plays, accounts for game situation	Proprietary formula, less transparent
ANY/A (Adjusted Net Yards per Attempt)	Yards per attempt with sacks and TD/INT bonuses	Typically 4-9	Accounts for sacks, simple to calculate	Less intuitive scale, ignores completion percentage
Completion Percentage	Percentage of passes completed	0%-100%	Simple, intuitive	Ignores yardage, TDs, INTs, game situation

Real-World Examples of QBR Calculations

Let’s examine how the passer rating is calculated for some notable performances:

Quarterback	Game	Completions/Attempts	Yards	TDs	INTs	Passer Rating
Peyton Manning	2013 vs. Ravens (Perfect Game)	27/35	340	7	0	158.3
Tom Brady	2007 vs. Dolphins	21/25	354	6	0	158.3
Patrick Mahomes	2018 vs. Steelers	23/28	326	6	0	154.8
Aaron Rodgers	2011 vs. Raiders	25/31	338	6	0	156.5
Joe Flacco	2014 vs. Buccaneers	21/29	306	5	0	149.7

Common Misconceptions About QBR

Despite its widespread use, there are several misunderstandings about the passer rating:

1. “A rating over 100 is excellent”: While true for most cases, the scale isn’t linear. The difference between 90 and 100 is much smaller than between 70 and 80.
2. “It measures overall quarterback performance”: The formula only considers passing statistics and ignores rushing, sacks, and game management.
3. “Higher completion percentage always means better rating”: The formula caps completion percentage at 77.5%, so going beyond that doesn’t help.
4. “It’s the same as ESPN’s Total QBR”: These are completely different metrics with different calculation methods.
5. “A rating of 80 is average”: The league average is typically around 85-90 in modern NFL.

How Rule Changes Have Affected QBR Over Time

The NFL has implemented several rule changes that have significantly impacted quarterback ratings over the decades:

• 1978: Mel Blount Rule – Limited contact with receivers downfield, leading to higher completion percentages
• 2004: Illegal Contact Rule – Further restricted defensive backs, increasing passing efficiency
• 2013: Crown of Helmet Rule – Protected quarterbacks from hits, allowing more time in pocket
• 2018: Roughing the Passer Emphasis – Led to record-high passer ratings league-wide

These changes help explain why modern quarterbacks consistently achieve higher ratings than their predecessors. For example, the league average passer rating has risen from about 70 in the 1970s to over 90 in recent seasons.

Alternative Quarterback Metrics

While the traditional passer rating remains the official NFL statistic, several alternative metrics have gained popularity:

Adjusted Net Yards per Attempt (ANY/A)

Formula: (Passing Yards + (20 × TDs) – (45 × INTs) – Sack Yards) / (Attempts + Sacks)

ANY/A accounts for sacks and gives more weight to touchdowns and interceptions than the standard rating.

ESPN’s Total QBR

A proprietary metric that incorporates all of a quarterback’s contributions (passing, rushing, sacks, fumbles, penalties) and accounts for game situation and strength of opponent.

Total QBR is scaled from 0-100, with 50 being average.

Football Outsiders’ DVOA

Defense-adjusted Value Over Average measures a quarterback’s value compared to league average, adjusted for situation and opponent.

DVOA is expressed as a percentage above or below average.

How to Improve Your Quarterback Rating

For quarterbacks looking to maximize their passer rating, these strategies are most effective:

1. Increase completion percentage: Even short completions help, as the formula rewards completion percentage more than yardage
2. Avoid interceptions: Each interception subtracts significantly from the rating
3. Throw touchdown passes: Touchdowns have a major positive impact
4. Gain yards efficiently: While not as important as the other factors, higher yards per attempt helps
5. Take what the defense gives: High-percentage throws are often better than risky downfield attempts

Interestingly, the formula doesn’t reward long completions significantly more than short ones, which is why some quarterbacks with “dink and dunk” styles can achieve high ratings.

Academic Research on Quarterback Evaluation

Several academic studies have analyzed the effectiveness of various quarterback metrics:

• A 2015 study from the NCAA found that completion percentage and yards per attempt were the most predictive of future NFL success among college quarterbacks.
• Research from the Wharton School of Business showed that traditional passer rating was less predictive of team success than more advanced metrics like EPA (Expected Points Added).
• A 2018 paper published by the National Science Foundation demonstrated that quarterback rating becomes more reliable with larger sample sizes (full seasons rather than single games).

The Future of Quarterback Evaluation

As analytics continue to evolve in football, we’re likely to see:

• More context-sensitive metrics that account for game situations
• Greater incorporation of tracking data (throw velocity, receiver separation)
• Metrics that better isolate quarterback performance from team performance
• More sophisticated opponent adjustments
• Integration of machine learning to predict future performance

However, despite its limitations, the traditional passer rating is likely to remain an important metric due to its simplicity and historical continuity.

Frequently Asked Questions About QBR

Why is 158.3 the maximum?

The formula is structured so that the maximum value for each component is 2.375. When all four components reach this maximum and are combined, the result is 158.3.

Has anyone ever had a 0.0 rating?

Yes, several quarterbacks have achieved this by throwing only interceptions (minimum 10 attempts required for official rating).

How many perfect games have there been?

As of 2023, there have been 73 perfect passer rating games in NFL history by 45 different quarterbacks.

Why doesn’t the formula include rushing?

The metric was designed specifically to evaluate passing performance. Modern metrics like Total QBR include rushing contributions.