Stat Explainer

NFL Calculators: Passer Rating, Pythagorean, 2-Point and 4th-Down Tools

Free interactive calculators — compute passer rating, Pythagorean expected win%, the 2-point vs. PAT decision, and a transparent 4th-down expected-points model. Pure math, your inputs.

By The NFL Analytics Editorial Team · Published June 15, 2026

Four interactive NFL calculators that run entirely in your browser. Each one shows the result, the exact formula, and a plain-English interpretation. Every number comes from your inputs and transparent math — no fabricated data, no black boxes.

These are honest math tools. The passer rating and Pythagorean tools use the canonical formulas; the 2-point and 4th-down tools are clearly-labelled expected-value models driven by the rates and estimates you enter.
Passer Rating Calculator QB

Enter a passing line and get the official NFL passer rating (0–158.3), broken into its four components.

Formula: rating = ((a+b+c+d)/6)×100 with a=((CMP/ATT)−.3)×5, b=((YDS/ATT)−3)×.25, c=(TD/ATT)×20, d=2.375−(INT/ATT)×25; each component capped to 0–2.375.

Pythagorean Expected Win% Calculator Team

Turn points scored and allowed into an expected win percentage — the number a team’s record tends to regress toward.

Formula: expected win% = PF^2.37 / (PF^2.37 + PA^2.37). The 2.37 exponent is the value commonly fit to NFL scoring.

2-Point vs. Extra-Point Calculator Decision

Compare the expected points of going for two against kicking the PAT, given your own conversion and make rates.

Formula: EV(2-pt) = 2 × conversion%; EV(PAT) = 1 × make%. Recommend the higher expected value. Break-even 2-pt rate = (PAT make%)/2.

4th-Down Decision Calculator Flagship

A transparent expected-points model built entirely from your inputs. Adjust the conversion, field-goal, and expected-points estimates and the recommendation for Go / Punt / Field Goal updates live. This is a model from your numbers, not league data.


Expected-points estimates (override to fit the situation)

Model (your perspective; opponent points count against you): Go = conv%×(EP convert) + (1−conv%)×(−opp EP fail); FG = fg%×3 + (1−fg%)×(−opp EP miss); Punt = −(opp EP after punt). The win-probability swing shown is a labelled rule-of-thumb scaling of the expected-points edge, not a fitted model.

Want the theory behind these numbers? Read the analytics explainers on passer rating, Pythagorean wins, two-point decisions, and fourth-down strategy.

More to explore

Plain-English guides to the metrics, and the full code-first tutorial.

Explainers Tutorials