⚾ FIP Calculator
Estimate pitcher effectiveness on outcomes they control: strikeouts, walks, hit batters, and home runs.
Use baseball decimals (.1 = 1 out, .2 = 2 outs). Example: 6⅔ innings = 6.2.
League-specific constant (MLB seasons usually range 3.0 – 3.3). Defaults to 3.1.
How to Use This Calculator
Gather Stat Line
Collect home runs allowed, walks, hit-by-pitches, strikeouts, and innings pitched.
Enter Baseball Innings
Use .1 and .2 to represent one or two outs. The calculator converts to decimal innings.
Adjust the FIP Constant
Keep the default 3.1 or plug in the season-specific constant you prefer.
Analyze the Result
Compare the FIP output to benchmarks below to understand the pitcher’s skill level.
Formula
FIP = [(13 × HR) + 3 × (BB + HBP) − 2 × K] ÷ IP + FIP constant
Fielding Independent Pitching (FIP) removes most defensive influence by focusing on the “three true outcomes” plus hit batters. The constant recenters the league average FIP to match league ERA for a specific season.
Variables
- HR: Home runs allowed
- BB: Walks issued
- HBP: Hit batters
- K: Strikeouts recorded
- IP: Innings pitched (decimal)
Example
Pitcher allows 20 HR, 60 BB, 5 HBP, with 210 K in 205.2 IP. FIP constant = 3.09.
FIP = [(13×20) + 3×(60+5) − 2×210] ÷ 205.67 + 3.09 = 3.15.
Understanding FIP
FIP was designed to isolate pitcher skill by focusing on outcomes that bypass defense. It pairs well with ERA, allowing you to identify pitchers who were unlucky (ERA > FIP) or fortunate (ERA < FIP).
Benchmark Guide
- < 2.75: Dominant ace-level performance
- 2.75 – 3.25: All-Star caliber season
- 3.25 – 4.00: Solid rotation contributor
- 4.00 – 4.50: Back-end starter / average
- > 4.50: Struggling—watch homer or walk rates
Tips for Analysis
- Compare FIP to ERA to separate skill from luck or defense.
- Review trends in K%, BB%, and HR/9; these feed directly into FIP.
- Use FIP- (100 = league average) for era-adjusted comparisons.
Frequently Asked Questions
Why use FIP instead of ERA?
ERA is influenced by team defense, official scoring decisions, and sequencing luck. FIP zeroes in on controllable outcomes to predict future ERA more reliably.
What is the FIP constant?
Each season, analysts compute a constant so that league-average FIP equals league-average ERA. The value typically falls between 3.0 and 3.3 in modern MLB.
Does FIP work for relievers?
Yes, but sample size matters. A volatile reliever might have huge swings thanks to a few homers or walks. Look at multi-season trends for better insight.
How is FIP different from xFIP?
xFIP replaces actual home runs with expected home runs using fly-ball rates and a league-average HR/FB rate. It smooths out homer luck even further.
Can I use FIP for fantasy baseball?
Absolutely. Target undervalued pitchers whose FIP is far lower than their ERA—they’re strong rebound or breakout candidates.