MLB FIP Calculator (Fielding Independent Pitching)
Calculate Fielding Independent Pitching (FIP) from home runs, walks, hit-by-pitch, strikeouts, and innings — a defense-independent pitcher stat on the ERA scale. Free.
MLB FIP Calculator
FIP — Fielding Independent Pitching — measures a pitcher using only the outcomes they directly control (home runs, walks, hit-by-pitch, strikeouts), stripping out defense and batted-ball luck. It's scaled to look like ERA, so a 3.20 FIP reads like a 3.20 ERA. Enter a pitcher's line to compute it.
How to Use the FIP Calculator
Enter the four outcomes
Home runs allowed, walks, hit-by-pitch, and strikeouts — the "three true outcomes" plus HBP that a pitcher controls without help from fielders. Find them on any box score or stat site (Baseball-Reference, FanGraphs).
Add innings pitched
Use baseball notation: 180.0 is 180 innings, 180.1 adds one out (⅓), 180.2 adds two outs (⅔). The tool converts the partial innings correctly.
Set the FIP constant
The constant rescales FIP to the ERA range and changes slightly each season (recently around 3.10–3.20). Use the value for the season you're analysing; FanGraphs publishes it. The default 3.10 is a reasonable modern figure.
Compare FIP to ERA
Because FIP is on the ERA scale, read it the same way. A FIP well below a pitcher's ERA suggests they pitched better than their runs allowed (bad defense or luck); a FIP above ERA suggests the reverse — and FIP tends to predict next-season ERA better than ERA itself.
Why FIP Beats ERA at Measuring a Pitcher
The Insight Behind Fielding Independent Pitching
Earned run average has measured pitchers for over a century, but it has a flaw: it credits or blames the pitcher for things the pitcher doesn't control. Once a ball is put in play, whether it becomes a hit or an out depends heavily on the defense behind the pitcher, the ballpark, and plain luck. A pitcher with great fielders and a spacious outfield will post a lower ERA than an identical pitcher stuck with poor defenders and a bandbox stadium. Voros McCracken's research around 2000 showed that pitchers have remarkably little control over the outcome of balls in play from year to year — what they do control are the "three true outcomes" that don't involve fielders at all: strikeouts, walks, and home runs. FIP, developed by Tom Tango, distills exactly those events into a single number, weighting each by its run value, and then adds a constant so the result sits on the familiar ERA scale.
The formula — (13×HR + 3×(BB+HBP) − 2×K) ÷ IP, plus a league constant — encodes the run impact of each event: a home run is the most damaging, walks and hit-batters add baserunners, and strikeouts are pure outs that prevent everything. Because it ignores balls in play entirely, FIP isolates pitcher skill from defensive support and sequencing luck. Its practical value is predictive: a pitcher whose ERA is far below his FIP is often "due" to regress as his luck normalises, while one whose ERA sits above his FIP may be a buy-low candidate. Front offices, fantasy players, and analysts lean on FIP for exactly this reason, and it underpins the more advanced versions (xFIP, which normalises home-run rate, and SIERA).
"A pitcher controls strikeouts, walks, and home runs; the defense and luck handle the rest. FIP scores only what's in the pitcher's hands — which is why it predicts next year's ERA better than this year's ERA does."
How to Read FIP — and Its Limits
On the ERA scale, the rough guideposts hold: a FIP around 3.20 or below is excellent, the low 4.00s are roughly league average, and the high 4.00s and up are poor. The gap between FIP and ERA is where the story lives — a large gap in either direction flags defense, ballpark, or luck effects worth investigating. FIP isn't perfect: it treats all home runs and all walks identically regardless of context, ignores a pitcher's possible skill at suppressing hard contact, and over a small sample (a few starts) it's noisy because a couple of home runs swing it sharply. It's most reliable over a full season or career. For the global cricket-and-baseball-curious audience, FIP is the baseball cousin of the broader analytics movement that also gave cricket its expected-runs and bowling models — the shared idea being to credit a player only for what they genuinely control and to separate skill from the noise of a single result.
10 Facts About FIP
FIP = Fielding Independent Pitching — it scores only HR, BB, HBP, and K.
It's scaled to ERA, so a 3.20 FIP reads like a 3.20 ERA.
Formula: (13×HR + 3×(BB+HBP) − 2×K) ÷ IP + constant.
The constant (~3.10) changes yearly so league FIP equals league ERA.
It strips out defense and balls-in-play luck, which pitchers barely control.
FIP was developed by Tom Tango, building on Voros McCracken's DIPS research.
FIP often predicts next year's ERA better than this year's ERA does.
A big ERA-minus-FIP gap flags lucky/unlucky or defense/park effects.
xFIP goes further by normalising a pitcher's home-run rate.
Rough scale: ≤3.20 excellent, low-4s average, high-4s+ poor.
Frequently Asked Questions
- FIP (Fielding Independent Pitching) is a pitching metric that measures a pitcher using only the outcomes they control without help from fielders — home runs, walks, hit-by-pitch, and strikeouts. It weights each by run value and adds a league constant so the result is on the same scale as ERA. The idea is to isolate true pitcher skill from defense, ballpark, and luck on balls in play.
- FIP = ((13 × HR) + (3 × (BB + HBP)) − (2 × K)) ÷ innings pitched, plus a league-specific constant of roughly 3.10. The weights reflect each event's run impact: home runs hurt most, walks and hit-batters add runners, and strikeouts are clean outs. The constant rescales the result to the league's ERA so FIP and ERA are directly comparable.
- The constant is the number added at the end to put FIP on the ERA scale. It's recalculated every season so that the league-average FIP exactly equals the league-average ERA that year, which is why it drifts (recently around 3.10–3.20) as run environments change. For accuracy, use the constant for the season you're analysing — FanGraphs publishes it. This calculator lets you enter it rather than hardcoding a value that goes stale.
- For measuring a pitcher's own skill and predicting future performance, generally yes. ERA includes runs that resulted from poor defense or unlucky bloops the pitcher didn't control, while FIP isolates what the pitcher does control. Studies show a pitcher's FIP predicts his next-season ERA better than his current ERA does. ERA still matters as a record of runs that actually scored; FIP is the better gauge of underlying skill.
- Because FIP is on the ERA scale, read it like ERA. As a rough guide, a FIP around 3.20 or lower is excellent (ace territory), the low 4.00s is about league average, and the high 4.00s and above is below average. Elite seasons can dip under 3.00. Context matters — the run environment and league average shift year to year — so compare a pitcher's FIP to that season's league average for the truest read.
- The gap reflects what FIP ignores: defense, ballpark, and luck on balls in play, plus the sequencing of hits. If your ERA is well below your FIP, your fielders, park, or good fortune helped you allow fewer runs than your strikeout/walk/home-run profile suggests — and you may regress. If ERA is above FIP, the opposite: you pitched better than your runs allowed, and better results may be coming. A persistent gap can also hint at a real skill (or weakness) at managing contact.
- Use standard baseball notation, where the decimal is outs, not tenths. 180.0 means 180 full innings; 180.1 means 180 and one out (⅓ of an inning); 180.2 means 180 and two outs (⅔). The calculator converts these correctly — 180.1 becomes 180.333 innings internally. Don't enter 180.33; enter 180.1 as it appears on the stat line.
- xFIP (expected FIP) is FIP with one extra adjustment: instead of using a pitcher's actual home runs allowed, it replaces them with the home runs they'd be expected to allow given their fly-ball rate and the league home-run-per-fly-ball rate. Because home-run rate is volatile year to year, xFIP is often even more predictive than FIP for pitchers with unusual home-run luck. This tool computes standard FIP; xFIP needs batted-ball data.
- It applies to any pitcher, but it's noisier over small samples. A few starts or a handful of relief innings can be swung sharply by one or two home runs, so a reliever's FIP over 20 innings is far less reliable than a starter's over a full season. FIP is most trustworthy across a large workload. For tiny samples, treat it as a rough indicator and lean on multi-year figures where possible.
- FIP was developed by analyst Tom Tango (Tom M. Tango), building on the Defense Independent Pitching Statistics (DIPS) research that Voros McCracken published around 2000, which first demonstrated that pitchers have little control over the outcome of balls in play. FIP became a mainstream stat through FanGraphs and is now one of the most widely cited pitching metrics in baseball analysis, fantasy, and front-office evaluation.
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