FIP Calculator (Fielding Independent)
Calculate FIP to evaluate pitcher performance independent of fielding. Uses strikeouts, walks, hit batters, and home runs for true skill measurement.
FIP Calculator (Fielding Independent)
Calculator
Adjust values & calculateEnter your values below. Every result is computed in your browser — no data is sent to any server.
Formula: FIP = ((13 x HR) + (3 x (BB + HBP)) - (2 x K)) / IP + FIP Constant
Worked example — FIP = 2.81 (Ace-Level performance)
Formula
FIP = ((13 x HR) + (3 x (BB + HBP)) - (2 x K)) / IP + FIP Constant
Where HR = Home Runs allowed, BB = Walks, HBP = Hit By Pitch, K = Strikeouts, IP = Innings Pitched, and FIP Constant is a league-specific adjustment (typically around 3.10) that scales FIP to match league-average ERA.
Worked Examples
Example 1: Ace Pitcher Season Analysis
Problem:A starting pitcher records 220 strikeouts, allows 18 home runs, 45 walks, 4 HBP over 200 innings pitched. FIP constant is 3.10.
Solution:FIP = ((13 x 18) + (3 x (45 + 4)) - (2 x 220)) / 200 + 3.10 = (234 + 147 - 440) / 200 + 3.10 = -59 / 200 + 3.10 = -0.295 + 3.10 = 2.81
Result:FIP = 2.81 (Ace-Level performance)
Example 2: Average Pitcher Evaluation
Problem:A pitcher has 120 strikeouts, 25 home runs allowed, 60 walks, 8 HBP in 170 innings. FIP constant is 3.10.
Solution:FIP = ((13 x 25) + (3 x (60 + 8)) - (2 x 120)) / 170 + 3.10 = (325 + 204 - 240) / 170 + 3.10 = 289 / 170 + 3.10 = 1.70 + 3.10 = 4.80
Result:FIP = 4.80 (Poor — pitcher is struggling with home runs and walks)
Frequently Asked Questions
What is FIP (Fielding Independent Pitching) and why is it important?
FIP, or Fielding Independent Pitching, is an advanced baseball statistic that evaluates a pitcher based solely on outcomes the pitcher can directly control: home runs allowed, walks issued, hit batters, and strikeouts recorded. Unlike ERA, which can be influenced by the quality of the defense behind a pitcher, FIP strips away those variables to provide a cleaner measurement of a pitcher's true skill level. FIP is scaled to look like ERA, so a pitcher with a 3.00 FIP is performing at the same level as a pitcher who would have a 3.00 ERA with league-average defense and luck on balls in play.
How is the FIP constant calculated and why does it change each season?
The FIP constant is a number added to the FIP formula to bring the league-average FIP in line with the league-average ERA for that particular season. It is calculated as: lgERA minus ((13 times lgHR plus 3 times (lgBB plus lgHBP) minus 2 times lgK) divided by lgIP). This constant changes every season because run-scoring environments fluctuate year to year due to factors like ball composition, strike zone enforcement, ballpark changes, and overall talent distribution. Typically, the FIP constant hovers around 3.10 to 3.20 in modern baseball. Using the correct constant for the appropriate season ensures accurate comparisons.
What is a good FIP value for a starting pitcher in Major League Baseball?
In modern MLB, a FIP below 3.00 is considered elite or ace-level performance, placing a pitcher among the top starters in the game. A FIP between 3.00 and 3.50 indicates an above-average pitcher who is a solid number two or three starter. A FIP between 3.50 and 4.00 is considered league average and typical for a mid-rotation starter. A FIP between 4.00 and 4.50 suggests below-average performance, while anything above 4.50 generally indicates a pitcher who is struggling significantly. These benchmarks can shift slightly depending on the overall run environment of the season being analyzed.
How does FIP differ from ERA and which metric is more predictive?
ERA measures the actual earned runs a pitcher allows per nine innings, while FIP measures expected performance based on strikeouts, walks, hit batters, and home runs only. The critical difference is that ERA includes outcomes affected by fielders, such as whether a ground ball becomes a hit or an out. Research has shown that FIP is more predictive of future ERA than a pitcher's current ERA itself, because BABIP (batting average on balls in play) tends to regress toward league average over time. A pitcher with a high ERA but low FIP is likely experiencing bad luck or poor defense and should improve, while the reverse suggests regression is coming.
What are the limitations of FIP as a pitching evaluation tool?
While FIP is a valuable metric, it has notable limitations. First, it treats all home runs equally regardless of whether they were solo shots or grand slams, and it does not account for the timing or context of events. Second, FIP assumes that all pitchers have equal ability to control balls in play, which research on ground-ball pitchers and fly-ball pitchers has shown is not entirely true. Third, FIP does not consider pitch quality metrics like spin rate, velocity, or movement that modern analytics now track. Variants like xFIP (which normalizes home run rates) and SIERA (which incorporates batted-ball data) attempt to address some of these shortcomings and may provide even more accurate assessments.
Why does the FIP formula weight home runs 13, walks 3, and strikeouts minus 2?
The coefficients come from the run values of each event, multiplied by nine so the result lands on a runs-per-nine-innings scale like ERA. A home run is worth roughly 1.4 runs to the offense, and 1.4 times nine is about 13. A walk or hit batter is worth around a third of a run, giving 3. A strikeout saves a couple of tenths of a run compared with an average ball in play, which becomes the minus 2. Dividing the weighted total by innings pitched then completes the per-nine rate.
How do I enter innings pitched when a stat line reads 180.1 or 180.2?
Baseball box scores write partial innings in thirds, not decimals: the digit after the point counts outs. 180.1 means 180 innings plus one out, or 180.333, and 180.2 means 180 plus two outs, or 180.667. Typing 180.1 straight into the innings field understates the denominator slightly and nudges FIP in the wrong direction. Convert first by adding .333 for one out or .667 for two outs, which matters most for relievers whose totals are small.
What is xFIP and when should I use it instead of FIP?
xFIP keeps the same structure but replaces the home runs a pitcher actually allowed with an expected total: his fly balls multiplied by the league home-run-per-fly-ball rate. The logic is that home-run-per-fly-ball rates bounce around far more than strikeout or walk rates, so a single season of home run luck distorts FIP. Reach for xFIP when a pitcher's home run total looks wildly out of line with his career norms, and stay with FIP when you want to charge him for the balls that actually left the yard.
Does FIP mean the same thing for relievers as for starters?
The formula is identical but the context is not. Relievers face batters in shorter bursts, often with a platoon advantage, and post higher strikeout rates as a group, so the same FIP represents weaker relative performance than it would from a starter. Small innings totals also make reliever FIP volatile, since two home runs across 60 innings move the figure sharply. FIP also ignores leverage and inherited runners, which are central to judging bullpen work.
What is FIP- and how does it differ from raw FIP?
FIP- rescales FIP so that 100 equals league average after adjusting for ballpark and the run environment of the season, with lower numbers better: an 80 FIP- is 20 percent better than average. Raw FIP is expressed in runs per nine innings and depends heavily on the era and the park, so a 3.60 in a high-scoring year with a hitter's park can be stronger work than a 3.40 in a pitcher's park. Use FIP- when comparing pitchers across seasons or across very different ballparks.
References
Reviewed for accuracy by Sher, Sports Science & Nutrition Specialist · Editorial policy
Related Calculators
🧮Fielding Percentage
Calculate fielding percentage with inputs, formulas, and instant results.
🧮xFIP Calculator (Expected FIP)
Calculate x fip (expected fip) with inputs, formulas, and instant results.
🧮Fielding Efficiency Index
Calculate fielding efficiency index with inputs, formulas, and instant results.
🧮DIY Sports Drink
Calculate diy sports drink with inputs, formulas, and instant results.
🧮BABIP Calculator — Balls in Play Average
Calculate babip (balls in play avg) with inputs, formulas, and instant results.
🧮Batting Average
Calculate batting average with inputs, formulas, and instant results.
🧮Catcher Pop Time
Calculate catcher pop time with inputs, formulas, and instant results.
🧮Era (earned Run Average)
Calculate era (earned run average) with inputs, formulas, and instant results.