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 C. B. Zakarian · Updated October 28, 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.
On their own pages: the 4th Down Calculator (yards to go and field position in, go / kick / punt out) the NFL Win Probability Calculator (score, time left and possession), the Passer Rating Calculator (every part and cap shown, checked against published ratings) and the Field Goal Calculator (kick distance and make chance from 2021-2025 kicks), each with a worked example. The NFL Playoff Picker lets you pick the rest of the 2026 season and see both conferences’ seeds under the NFL’s tiebreakers.
Enter a passing line and get the official NFL passer rating (0–158.3), broken into its four components. The full page adds a worked example and the cap table.
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.
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.
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.
Enter the yards to go and where the ball is. The card prices going for it, a field goal and a punt in expected points with the site’s simplified illustrative model, the same one the 4th Down Calculator page and the Tools page run, so all three give the same answer for the same situation.
Model (simplified and illustrative; your perspective, so the opponent’s expected points count against you): the conversion chance is 68% on 4th-and-1 and falls by a factor of e−0.085 for each extra yard to go; the field-goal chance is the curve fitted on the 5,352 NFL field-goal tries of 2021-2025 (the one the Field Goal Calculator uses), in kick distance = yards to the goal line + 18, treated as 0% beyond 68 yards. Go = conversion% × EP(1st-and-10 after converting) − (1 − conversion%) × opponent EP at the spot; FG = make% × 3 − (1 − make%) × opponent EP after a miss (at the spot of the kick, 8 yards behind the line, or its 20); Punt = −opponent EP after a 40-yard net punt. The full formula, a worked example and a distance table are on the 4th Down Calculator page.
Plain-English guides to the metrics, and the full code-first tutorial.
Explainers TutorialsNothing here is betting advice, and no number on this page predicts any single game. Sports betting is legal only in some jurisdictions and only for adults (21+ in most U.S. states). If betting stops being entertainment, call or text 1-800-GAMBLER. Read the full disclaimer.