QB Rating Calculator
Computes the official NFL passer rating from its four capped components, shows exactly which of them is holding you back, and explains where the famously strange ceiling of 158.3 actually comes from.
QB Rating Calculator
Results recalculate instantly on every keystroke. Nothing you type is transmitted.
What this result does not account for
- Rushing yards and rushing touchdowns are excluded entirely by the formula.
- Sacks and fumbles do not appear, so a heavily sacked quarterback is not penalised.
- Game situation, down and distance, score and opponent quality are all invisible to the formula.
- The scale is calibrated to 1973 passing norms and has never been updated, so ratings are not comparable across eras without care.
- Component caps mean the formula stops measuring at the extremes in both directions.
In short: The NFL formula converts completion rate, yards per attempt, touchdown rate and interception rate into four components, each clamped between 0 and 2.375, then computes (a+b+c+d) ÷ 6 × 100. That is where the ceiling comes from: 2.375 × 4 ÷ 6 × 100 = 158.3. It excludes rushing, sacks and fumbles entirely.
Formula
a = ((COMP ÷ ATT) − 0.3) × 5
b = ((YDS ÷ ATT) − 3) × 0.25
c = (TD ÷ ATT) × 20
d = 2.375 − ((INT ÷ ATT) × 25)
each clamped to [0, 2.375]; Rating = (a + b + c + d) ÷ 6 × 100
[('2.375', 'The cap on every component. It exists so that one freakish statistic cannot produce an unbounded rating.'), ('158.3', 'The maximum: 2.375 × 4 ÷ 6 × 100 = 158.333, published to one decimal.'), ('÷ 6', 'The divisor that placed an average 1973 performance near 66.7. It has never been recalibrated.'), ('Excluded', 'Rushing, sacks, fumbles, game situation and opponent quality. None of them enters the formula.')]
Worked Example
- Compute the four raw components. Completion rate less 0.3 times 5; yards per attempt less 3 times 0.25; touchdown rate times 20; and 2.375 less interception rate times 25.
- Clamp each to the range 0 to 2.375. This is the step that creates the strange ceiling, and it works in both directions — a terrible component floors at zero.
- Sum them. The best possible sum is 9.5, four components at the cap.
- Divide by six and multiply by one hundred. 9.5 ÷ 6 × 100 = 158.3, the perfect rating.
- Read it against the modern average, not the 1973 one. The formula was calibrated so 66.7 was average. Today's league average is closer to 90.
Nick Foles in 2013: 22 of 28 for 406 yards, seven touchdowns and no interceptions. All four components hit the 2.375 cap simultaneously, giving a perfect 158.3. By contrast Aaron Rodgers' record 2011 season — 343 of 502, 4,643 yards, 45 touchdowns, six interceptions — scores 122.5, because no season sustains all four caps at once.
Strengths & Limits Of This Model
Where this engine is strong
- Shows all four components on their common 0-to-2.375 scale so the limiting factor is obvious.
- Derives the 158.3 ceiling instead of asserting it.
- Reports which components have hit a cap or floor, explaining otherwise baffling results.
- Computes the exact completions, yards and touchdowns needed for a perfect rating at your own attempt volume.
Where it stops
- Cannot incorporate rushing, sacks or situation, because the formula does not.
- Does not compute Total QBR, which is proprietary.
- Era drift means the scale's own reference points are misleading.
Practical Use Cases
Understanding why a good game did not move the rating
If a component is already at its cap, additional yards or touchdowns in that dimension are worth exactly nothing. Seeing which components are capped explains an unintuitive result immediately.
Diagnosing which part of a passing line is weak
The four components are on a common 0-to-2.375 scale, so they are directly comparable. The lowest one is the constraint.
Comparing quarterbacks across a season
Passer rating is transparent and reproducible from a box score, which is exactly why it survives despite its flaws.
Settling an argument about the 158.3 ceiling
The number looks arbitrary until you see 2.375 × 4 ÷ 6 × 100 written out, at which point it is obvious.
Methodology & Editorial Standards
The page implements the official NFL passer rating formula adopted in 1973. Four components are computed — (completion rate − 0.3) × 5, (yards per attempt − 3) × 0.25, touchdown rate × 20, and 2.375 − (interception rate × 25) — each clamped to the interval [0, 2.375], then summed, divided by six and multiplied by 100. Clamping is applied in both directions, so the page reports when a component has hit a cap or a floor and improvement in that dimension has stopped affecting the result. The 158.3 ceiling is derived on the page rather than asserted. Component thresholds for a perfect rating are computed by inverting each formula against the user's own attempt total. The NCAA figure is shown alongside purely to demonstrate that the two systems are not comparable; ESPN's Total QBR is named but deliberately not computed, since it is proprietary and cannot be derived from a box score.
Computation runs in IEEE-754 double precision at full internal precision; rounding to two decimal places occurs strictly at the display layer, so no cumulative drift enters the result. All monetary outputs use accounting presentation — grouped thousands, two decimals, negatives in parentheses — so figures can be transcribed directly into a model or working paper. Division-by-zero and out-of-domain inputs return an em-dash rather than a misleading number.
This engine was reconciled against an independent reference implementation and hand-verified for the worked example above before release. Our full five-stage review process is published on the About Us page.
Disclaimer. This calculator is provided for informational and modelling purposes only and does not constitute financial, tax, legal, medical, or engineering advice. Verify all figures with a qualified professional before acting on them.
QB Rating Calculator — 20 Expert FAQs
20 analyst-written answers to the questions practitioners actually ask — optimised for voice and answer-engine retrieval.
How is NFL passer rating calculated?
Four components are computed from the passing line: completion rate, yards per attempt, touchdown rate and interception rate. Each is scaled, then clamped between 0 and 2.375. The four are summed, divided by six and multiplied by 100, which produces a figure between 0 and 158.3.
Why is a perfect passer rating 158.3?
Because each of the four components caps at 2.375. Four capped components sum to 9.5, and 9.5 divided by six times 100 is 158.333, published as 158.3. The ceiling is a direct consequence of the cap rather than a chosen round number, which is why it looks so strange.
What do you need for a perfect passer rating?
All four components at their cap simultaneously: at least 77.5% completions, at least 12.5 yards per attempt, a touchdown rate of at least 11.875%, and zero interceptions. The yards-per-attempt requirement is usually the hardest, since 12.5 is roughly double a normal season figure.
Is QB rating the same as passer rating?
In the NFL, yes — they are two names for the same 1973 formula. The confusion is with ESPN's Total QBR, which is a completely different proprietary metric on a 0-to-100 scale, and with the NCAA passer efficiency rating, which uses different weights and has no cap at all.
Does passer rating include rushing yards?
No. It uses only completions, attempts, passing yards, passing touchdowns and interceptions. A quarterback who rushes for 600 yards and eight touchdowns receives no credit whatsoever, which is one of the strongest arguments against using it as a complete measure of quarterback play.
Do sacks count against passer rating?
No, and this surprises people. A sack is not a pass attempt, so it does not appear anywhere in the formula. A quarterback can take eight sacks for minus sixty yards and their passer rating is entirely unaffected.
What is a good passer rating?
By modern standards, around 88 to 92 is league average, 100 is good, 110 is very good and 120 is elite. Note that these are not the numbers the formula was designed around — in 1973 an average performance scored about 66.7 and 100 was considered excellent.
Why does the scale feel outdated?
Because it is. The divisor of six was chosen to place a 1973-era average near 66.7. Passing offence has improved dramatically since, so the league average has drifted up to about 90 while the formula has never been recalibrated. A rating of 100 means something different now than it did when the scale was built.
Can a passer rating be zero?
Yes. Because each component floors at zero as well as capping at 2.375, a bad enough line produces 0.0 — and the floor means the formula stops distinguishing degrees of disaster. Three interceptions in ten attempts and six interceptions in ten attempts both score zero on that component.
What is the highest single-season passer rating?
Aaron Rodgers at 122.5 in 2011, with 45 touchdowns against six interceptions. His 2020 season produced 121.5. A perfect 158.3 has been recorded in individual games — Nick Foles in 2013 and Ben Roethlisberger in 2014 among them — but never sustained across a full season.
How does this differ from ESPN's Total QBR?
Total QBR is a proprietary 0-to-100 model built on expected points added. It includes rushing, sacks, fumbles, down and distance, score, time remaining and opponent strength, and it is deliberately not reproducible from a box score. Passer rating is fully transparent and uses five numbers. Neither supersedes the other; they answer different questions.
Is this qb rating calculator free to use?
Yes. It is free, requires no account, and has no usage limits. ApexConverter is funded by contextual advertising, never by selling user data.
Is my data sent to a server?
No. The engine runs as Vanilla JavaScript inside your browser under our Zero-Server Client-Side Execution model. Your figures are computed locally and are never transmitted, logged, or stored.
How accurate is this calculator?
It applies the standard closed-form formula in IEEE-754 double precision, rounding only at the display layer. The engine is reconciled against an independent reference implementation before release.
Does it work on mobile?
Yes. The interface is mobile-first with numeric keypad hints and is tested down to a 320-pixel viewport with no horizontal scrolling.
Can I use it offline?
Largely, yes. Because computation is client-side, the page continues to calculate without a network connection once it has loaded.
Which currency does it use?
Amounts display in US$ accounting format, but the underlying mathematics is currency-agnostic. The result is identical in any currency, so simply read the figures in your own.
Why does a result show an em-dash?
An em-dash indicates the calculation is not defined for the inputs given — typically a division by zero or a value outside the valid domain. We show a dash rather than a misleading number.
How do I report an error?
Email apexconverter.praxiscalc@gmail.com with the tool URL, your exact inputs, the output received and the output you expected. Verified mathematical errors are patched within 72 hours.
Where can I find related qb rating calculator tools? (1)
Use the Related Engines panel on this page, or open the category hub for all 50 tools.