FIP Calculator (Fielding Independent Pitching)
Calculate a pitcher’s FIP (Fielding Independent Pitching) from innings, home runs, walks, hit batters and strikeouts, compare it with ERA and see where it ranks on the FanGraphs scale.
How it works
FIP = (13 × HR + 3 × (BB + HBP) − 2 × K) ÷ IP + FIP constant · the constant (≈ 3.10) = league ERA − league (13 × HR + 3 × (BB + HBP) − 2 × K) ÷ IP, so league-average FIP equals league-average ERA.
Fielding Independent Pitching, created by Tom Tango, keeps only the outcomes a pitcher controls without his fielders — home runs, walks, hit batters and strikeouts — and weights them by their average run value. The constant puts the number on the familiar ERA scale. Because balls in play depend heavily on defense and luck, FIP usually predicts next season’s ERA better than ERA itself. FanGraphs rates about 3.20 as excellent, 4.20 as average and 5.00 as awful.
Worked example
A pitcher throws 180 innings with 20 home runs, 50 walks, 5 hit batters and 190 strikeouts. FIP = (13 × 20 + 3 × 55 − 2 × 190) ÷ 180 + 3.10 = (260 + 165 − 380) ÷ 180 + 3.10 = 0.25 + 3.10 = 3.35, which rates as Great. His 3.80 ERA is 0.45 higher than his FIP, a hint of bad luck or weak defense behind him.
Sources: FanGraphs Sabermetrics Library — FIP · FanGraphs — Guts! (yearly FIP constants)
Frequently asked questions
What is a good FIP?
On the FanGraphs scale, 3.20 or lower is excellent, about 3.50 great, 3.80 above average, 4.20 average, 4.40 below average, 4.70 poor and 5.00 or more awful. Like ERA, lower is better.
What is the FIP constant?
It is the number that makes league-average FIP equal league-average ERA in a given season. It changes slightly every year and is usually between 3.0 and 3.3 in MLB; 3.10 is a good default when you don’t know the exact season value.
Why is FIP different from ERA?
ERA counts every run, including those caused by bad defense, bloop hits and bullpen help. FIP only looks at strikeouts, walks, hit batters and home runs, so a large ERA − FIP gap often signals luck or defense that tends to even out.
How do I enter partial innings?
Use baseball notation: 180.1 means 180⅓ innings and 180.2 means 180⅔. The calculator converts it to a true decimal (180.33 or 180.67) before dividing.
What is xFIP?
xFIP replaces a pitcher’s actual home runs with the league-average home-run-per-fly-ball rate times his fly balls. It removes home-run luck too, but needs batted-ball data, so this calculator uses standard FIP.
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This calculator is for educational purposes. Double-check important results before acting on them.