If your ERA looks ugly but you feel like you’ve been pitching well, this FIP calculator will tell you whether your ERA is lying. Fielding Independent Pitching (FIP) strips out the strikeouts a third baseman should have made, the bloop singles that fell in front of your right fielder, and every other ball in play that depends on the seven defenders behind you. What’s left is a stat that measures only the things you actually controlled on the mound — strikeouts, walks, hit-by-pitches, and home runs. Plug in those four numbers plus your innings pitched, and the calculator returns your FIP on the same scale as ERA, so you can compare them directly.

What Fielding Independent Pitching Actually Measures

FIP was developed in the early 2000s by sabermetrician Tom Tango as a response to a frustrating problem: traditional ERA blames pitchers for things they cannot control. However, ERA counts every earned run, regardless of whether it scored on a Gold Glove play or a misjudged fly ball. Therefore, two pitchers with identical stuff and identical pitch sequencing can finish a season with wildly different ERAs simply because one had Andrelton Simmons behind him and the other had a converted second baseman at shortstop.

FIP fixes that by isolating the four outcomes that don’t involve fielders. Specifically, a strikeout is the pitcher’s. A walk is the pitcher’s. A hit-by-pitch is the pitcher’s. A home run, when it leaves the yard, is the pitcher’s. Everything else — ground balls, line drives, fly balls that stay in play — gets discarded from the equation. The result is a number that maps onto the ERA scale, so a 3.50 FIP is read the same way as a 3.50 ERA, but it reflects only the events the pitcher truly owned.

FIP is similar to ERA, but it focuses solely on the events a pitcher has the most control over — strikeouts, unintentional walks, hit-by-pitches and home runs. It entirely removes results on balls hit into the field of play.

— Major League Baseball

Importantly, this is why analysts treat FIP as a better predictor of next-season ERA than current ERA itself. ERA fluctuates with defensive luck and sequencing; FIP captures the underlying skill. Consequently, if your ERA is 5.20 but your FIP is 3.80, the smart bet is that your ERA will fall closer to that 3.80 over a larger sample. Conversely, an ERA of 2.50 paired with an FIP of 4.10 is a warning sign that regression is coming.

The FIP Calculator Formula and Constant

The math behind any FIP calculator is straightforward once you know the formula. Specifically, the equation is:

FIP = ((13 × HR) + (3 × (BB + HBP)) − (2 × K)) / IP + FIP constant

The constant pulls the result onto the ERA scale.

Each weight reflects the run value of that event. Notably, a home run is worth roughly 13 times more than a generic out, a walk or hit-by-pitch is worth 3, and a strikeout saves about 2 runs compared to letting the ball go in play. These weights aren’t arbitrary; they come from linear-weights run-expectancy tables that sabermetricians built from decades of play-by-play data.

The FIP constant exists for a single reason: to slide the raw output up so the average MLB pitcher’s FIP matches the league’s average ERA. Without it, FIP would land somewhere around zero, which would be confusing to anyone who grew up reading ERA. The constant changes slightly every season because league-wide HR, BB, HBP, K, and IP totals change. For example, the 2019 FIP constant was 3.214 in a high-offense environment, while the 2024 league constant settled near 3.10 as offense cooled and strikeout rates climbed. Therefore, this FIP calculator uses 3.10 as the default 2026 constant, which is accurate enough for any individual pitcher analysis. If you want a more precise answer for a specific season, FanGraphs publishes the official constant in its sabermetrics library.

How to Use the FIP Calculator Step by Step

The FIP calculator above takes five inputs. However, getting accurate results depends on knowing exactly what each one means and where to find the numbers in your boxscore or season stats.

1. Home runs (HR): Total home runs you’ve allowed. Inside-the-park home runs count too, even though they involve fielding.
2. Walks (BB): Use unintentional walks if your stat sheet separates them. If it doesn’t, total walks works fine; the difference is usually marginal.
3. Hit-by-pitches (HBP): Every batter you plunked. This counts whether the hitter ducked into a curveball or you genuinely lost a fastball arm-side.
4. Strikeouts (K): Both swinging and looking. Notably, every strikeout is worth nearly two runs of FIP improvement, which is why power pitchers run such low FIPs.
5. Innings pitched (IP): Use your stat-sheet number with thirds shown as decimals — 60.1 IP is 60 and one-third innings. Importantly, the calculator handles the conversion internally, but if you enter the number wrong, the FIP will be wrong by the same proportion.

Once those five fields are filled in, click Calculate FIP. The output reads on the same scale as ERA, and the visual gauge tells you immediately whether your number is excellent, above average, average, or below average. Furthermore, the gauge updates dynamically, so you can stress-test scenarios — what would your FIP look like if you’d cut three home runs out, or if you’d added ten strikeouts? Ultimately, that’s how you turn a calculator into a coaching tool.

Interpreting Your Result: The FIP Calculator Scale

A raw FIP number doesn’t mean much without context. Therefore, the FIP calculator scale benchmarks your result against league norms so you know where you stand. The thresholds below are the standard ones used by FanGraphs and most front offices, calibrated to a roughly league-average run environment.

FIP Range	Tier	What It Means
Below 3.00	Excellent	True ace territory. Among the best 5–10% of MLB starters.
3.00 – 3.49	Great	Top-of-rotation arm. Reliable, dominant outings.
3.50 – 3.99	Above Average	Solid mid-rotation starter or high-leverage reliever.
4.00 – 4.49	Average	League-average pitcher. Useful, replaceable.
4.50 – 5.00	Below Average	Back-of-rotation or middle-relief profile.
Above 5.00	Poor	Likely out of a job at the major league level.

For amateur, college, and high school pitchers, these thresholds shift. Specifically, college aces routinely run FIPs in the low 2s, while a typical Division I starter sits around 3.50–4.00. High school numbers vary so widely by league that comparing your FIP to a teammate’s is more useful than comparing it to MLB benchmarks. Furthermore, sample size matters enormously: an FIP over 20 innings will swing dramatically with one bad outing, while an FIP over 150 innings is much more stable. A general rule is that FIP starts to mean something around 50 innings for a starter and 25 innings for a reliever.

A Worked Example with the FIP Calculator

Numbers in isolation are abstract. Therefore, here’s how the FIP calculator processes a real-looking line. Imagine a starter who throws 180 innings with the following totals: 20 home runs, 50 walks, 6 hit-by-pitches, 195 strikeouts.

• 13 × 20 HR = 260
• 3 × (50 BB + 6 HBP) = 3 × 56 = 168
• 2 × 195 K = 390
• (260 + 168 − 390) / 180 = 38 / 180 = 0.211
• 0.211 + 3.10 (constant) = 3.31 FIP

That 3.31 lands squarely in the “Great” tier — the kind of season a No. 2 starter on a contender turns in. Now consider what changes if those 20 home runs were 12 instead. Re-run the math: 13 × 12 = 156, so the numerator drops by 104. Divide by 180 and the FIP improves by about 0.58 runs, landing at 2.73. That’s the difference between a strong starter and a Cy Young candidate, and it’s why home-run prevention is the single biggest lever a pitcher can pull. In contrast, swapping ten extra strikeouts for ten balls in play only moves FIP by about 0.11. Therefore, the FIP calculator makes these tradeoffs visible in seconds, which is the whole point of running the math.

FIP vs. ERA, WHIP, xFIP, and SIERA

FIP isn’t the only pitching metric, and it’s not always the right one. Here’s how it compares to the other stats every analyst checks alongside it.

ERA

ERA is the descriptive number — what actually happened. FIP is the diagnostic number — what should have happened given pitcher-controllable events. Use both together. If they’re close, your ERA is real. If FIP is much lower, you’ve been unlucky on balls in play. If FIP is much higher, you’ve been bailed out by your defense. Our ERA Calculator handles the descriptive side.

WHIP

WHIP measures baserunner prevention — walks plus hits per inning. It’s a useful traffic-control stat, but it doesn’t separate hits from defense. Specifically, a pitcher with poor defense behind him has an inflated WHIP through no fault of his own. FIP doesn’t have that problem. Run them side by side using our WHIP Calculator for the cleanest read on a pitcher’s profile.

xFIP

xFIP — expected FIP — replaces a pitcher’s actual home-run total with what they would have allowed at a league-average HR/FB rate. The reasoning is that home-run rate on fly balls is largely luck-driven year to year. Consequently, xFIP is more predictive of next-year ERA than FIP for most pitchers. The exception is extreme groundball or extreme fly-ball pitchers, who genuinely allow home runs at non-average rates. For them, FIP can be more accurate.

SIERA

SIERA (Skill-Interactive ERA) is the most sophisticated of the bunch. It includes batted-ball type — ground balls, line drives, fly balls — and adjusts for park effects. Research from FanGraphs and others shows SIERA is the single most predictive of future ERA, with a slight edge over xFIP and a meaningful edge over FIP. However, SIERA is harder to calculate by hand, which is why FIP remains the workhorse stat for most fans and coaches. Essentially, FIP gives you 90% of the value with 20% of the math.

The Best FIP Seasons in MLB History

Looking at the all-time FIP leaderboard puts your own number in perspective. The single-season record belongs to Satchel Paige, who posted a 1.18 FIP in 1946 — though that was in the Negro Leagues’ final years against varying competition. The modern-era leaders are nearly as untouchable.

• Pedro Martínez, 1999: 1.39 FIP over 213.1 innings with 313 strikeouts. Widely considered the greatest pitching season ever.
• Christy Mathewson, 1908: 1.29 FIP — dead-ball era, but still a staggering display of control.
• Walter Johnson, 1910: 1.38 FIP, the first generation of overpowering fastballs.
• Clayton Kershaw, 2014: 1.81 FIP. The defining modern peak — won both the MVP and Cy Young.
• Jacob deGrom, 2018–2021: Active career FIP under 2.75, the lowest of any pitcher with 1,000+ innings since the integration era.

For career FIP, dead-ball era pitchers dominate the leaderboard because home runs were vanishingly rare. Ed Walsh’s 2.02 career FIP is the all-time record, with Rube Waddell at 2.03 and Satchel Paige at 2.19 rounding out the top three. Among modern arms, Mariano Rivera’s 2.76 FIP across nearly 1,300 relief innings stands out as the best sustained performance of the past 50 years.

How to Improve Your FIP — Practical Guidance

Looking at the FIP formula tells you exactly where to spend your training time. The four levers, in order of impact, are home runs allowed, strikeout rate, walk rate, and hit-by-pitches. Importantly, that ranking is not about which is hardest to fix; it’s about which produces the biggest FIP swing per unit of improvement.

Cut Home Runs First

Each home run is worth 13 in the FIP numerator. Therefore, cutting two home runs from a 180-inning season improves FIP by roughly 0.14 runs — a meaningful chunk. The fastest way to allow fewer home runs is to keep the ball down. Specifically, fly balls hit at launch angles between 25 and 35 degrees account for the majority of home runs at every level. Pitches at the knees produce ground balls; pitches up in the zone produce barrels. Live arm-side fastballs that drift to the middle of the plate at belt height are the worst offenders.

Build Your Strikeout Rate

Each strikeout shaves 2 from the FIP numerator. Adding 20 strikeouts to a season shifts FIP by about 0.22. Most strikeout gains come from pitch design, not effort. In particular, a true swing-and-miss secondary pitch — usually a slider, splitter, or sweeper — is the difference between a 20% K-rate pitcher and a 30% K-rate pitcher. Modern player-development programs have made high-spin breaking balls accessible to amateurs through pitch-tracking tech like Rapsodo and TrackMan.

Trim Walks and Hit-by-Pitches

Walks and HBPs each cost 3 in the numerator. Cutting 10 walks from a season is worth roughly 0.17 runs of FIP. The training answer here is unsexy: throw more strike one. Pitchers who get ahead 0-1 walk hitters at less than half the rate of those who fall behind 1-0. Furthermore, command beats velocity for FIP improvement at every level below the absolute top of MLB. A 90 mph fastball thrown for strikes will produce a better FIP than a 96 mph fastball thrown for balls.

When the FIP Calculator Lies (And When to Trust It)

FIP is a powerful tool, but it has known blind spots. Knowing them keeps you from drawing the wrong conclusion from your number.

• Extreme groundball pitchers get penalized. A pitcher who induces weak contact at an elite rate can outperform his FIP indefinitely. Brandon Webb, Tim Hudson, and Roy Halladay all sustained ERAs well below their FIPs across long careers.
• Park effects are baked in. A pitcher in Coors Field has an inflated home-run rate by environment, not skill. Park-adjusted ERA estimators like SIERA and xFIP correct for this; raw FIP does not.
• Sample size dominates. Across small samples — say, a 30-inning relief stint — a single bad outing can warp FIP just as much as ERA. Consequently, a reliever with a 6.00 FIP across April will often regress to 3.50 by September with no meaningful change in stuff.
• Pitching to contact is undervalued. FIP treats every ball in play identically, which means a pitcher who pounds the bottom of the zone and gives up weak grounders gets no FIP credit for that skill. SIERA was specifically built to fix this.

Despite the caveats, FIP remains the right starting point for almost any pitching analysis. Specifically, when paired with ERA and a strikeout-to-walk ratio, the three numbers together give you a complete profile of what a pitcher is doing and why their results look the way they do. The FIP calculator above is the fastest way to generate the FIP component without copying numbers into a spreadsheet.

FIP Calculator FAQ

What is a good FIP for a high school pitcher?

For varsity high school pitching, anything below 3.50 is excellent and indicates Division I recruitability. Average tends to land around 4.00–4.50 because hit-by-pitches and walks both run higher at the amateur level than in professional baseball. Notably, the FIP constant for amateur play is harder to pin down because there’s no league-wide stat tracking, so most coaches use the standard 3.10 constant from MLB and accept that the result is approximate.

Can the FIP calculator be used for softball?

Yes, the formula works identically for softball — strikeouts, walks, hit-by-pitches, and home runs are all weighted the same way. However, the interpretation thresholds differ because softball’s run environment is different. Specifically, a strong college softball FIP runs around 2.00–2.50, while a 3.00 FIP that’s elite in baseball would be merely above-average in softball because run scoring is generally lower. Furthermore, the constant should be adjusted to the specific softball league’s average ERA if you want a precise comparable.

Why does FIP use 13, 3, and 2 as the weights?

The weights come from linear-weights run-expectancy tables, which calculate the average run impact of each event. Specifically, a home run produces about 1.4 runs above an out, a walk or HBP about 0.33, and a strikeout saves about 0.12 runs versus a generic batted ball. Multiplying by 13, 3, and 2 (and dividing by 9 innings, which is built into the formula) calibrates everything to the ERA scale. Importantly, these weights are stable across eras even as run environments shift.

Should I trust FIP or ERA more?

For evaluating past performance, ERA tells you what actually happened. For predicting future performance, FIP is more reliable. Therefore, if you’re projecting a pitcher into the next season — whether for fantasy, scouting, or roster decisions — FIP is the better signal. If you’re describing a season that already finished, ERA is the right number. The smartest analysts use both: ERA for the story, FIP for the explanation.

How accurate is the FIP calculator with a 3.10 constant?

For the 2024–2026 MLB run environment, the 3.10 constant is accurate within a few hundredths of a run. Specifically, the actual league-calculated constant has hovered between 3.08 and 3.14 for the last three seasons. Consequently, if you want a precise apples-to-apples comparison with the official FanGraphs FIP, plug in the exact season constant from their leaderboard. For most amateur and analytical uses, 3.10 is more than close enough.

Does the FIP calculator account for park factors?

No. Raw FIP is park-neutral by design — it counts home runs as home runs regardless of where they were hit. Therefore, a pitcher in a hitter-friendly park will run a slightly inflated FIP compared to his true talent, while a pitcher in a pitcher’s park benefits from the inverse. To park-adjust, you can use FIP- (FIP minus) from FanGraphs, where 100 is league average and lower is better. SIERA also bakes in park context.

Related Baseball Tools and Calculators

FIP is one piece of the modern pitching analytics stack. To get the full picture of a pitcher’s season, run their numbers through the related calculators below. Each tool uses the same direct, results-first approach as this FIP calculator.

• ERA Calculator — the descriptive companion to FIP. Pair the two to spot defense-driven luck.
• WHIP Calculator — baserunner prevention. The third number every pitching breakdown needs.
• Batting Average Calculator — flip the analysis to the hitter side.
• OPS Calculator — the offensive analog to FIP for context-free hitter evaluation.
• On-Base Percentage Calculator — the foundational rate stat for hitter quality.
• 13 Run Pool — a free MLB game where you pick a team and chase every run total from 0 to 13.

Updated May 2026 — uses the current 3.10 FIP constant and includes Jacob deGrom, Chris Sale, and Logan Webb among the active leaderboard reference points. The FIP calculator above runs the math in real time, so refresh the page if you want to test multiple pitcher lines back-to-back.