FIP Calculator
Calculate Fielding Independent Pitching (FIP), which grades a pitcher only on the outcomes they control - home runs, walks, hit-by-pitch, and strikeouts. Enter those plus innings pitched (outs as .1 and .2) and the season constant to get FIP on the familiar ERA scale.
Example: with Home runs allowed (HR) 18 · Walks (BB) 45 · Hit by pitch (HBP) 5 · Strikeouts (K) 180 · Innings pitched (e.g. 6.2 = 6 and 2 outs) 190 → FIP: 3.23.
- True innings pitched190.00 innings
- QualityAbove average
Computed by the calculator below using its default values. Change any input to see your own numbers.
FIP strips out defense and luck, keeping only strikeouts, walks, hit-by-pitch and home runs. A constant near 3.10 puts it on the same scale as ERA, so read it the same way.
What FIP tries to fix
Earned run average blends the pitcher's work with the defense behind them and a lot of luck on balls in play. Fielding Independent Pitching cuts that out. It keeps only the three true outcomes a pitcher controls almost entirely - strikeouts, walks (with hit-by-pitch), and home runs allowed - weights them, divides by innings, and adds a constant to land on the ERA scale. The result estimates what a pitcher's ERA should have been given those outcomes.
That is why FIP often predicts a pitcher's future ERA better than their current ERA does: a low ERA propped up by great defense or lucky bounces tends to regress toward a higher FIP.
The weights and the constant
The formula multiplies home runs by 13, walks plus hit-by-pitch by 3, and strikeouts by minus 2, reflecting how much each event helps or hurts run prevention. Dividing by innings pitched turns it into a rate. The constant - typically around 3.10, though it is recalculated each season so that league FIP equals league ERA - simply shifts the scale so a FIP of 4.00 means about what an ERA of 4.00 means. Lower is better, exactly like ERA.
How it’s calculated
FIP = (13 x HR + 3 x (BB + HBP) - 2 x K) / IP + constant. The constant is set each season so league FIP matches league ERA and is near 3.10; adjust it to the season if you have the exact value. Innings pitched use baseball notation, where .1 = one out (one-third) and .2 = two outs (two-thirds).
FIP assumes league-average results on balls in play, so it deliberately ignores the pitcher's actual hits and defense. It is an estimate of run prevention skill, not a record of runs actually allowed.
FIP quality guide
| FIP | Rating |
|---|---|
| Under 3.00 | Excellent (ace) |
| 3.00-3.75 | Above average |
| 3.75-4.25 | League average |
| 4.25-4.75 | Below average |
| Over 4.75 | Poor |
FIP is scaled to look like ERA using a constant near 3.10 that changes slightly each season. Lower is better.
Common mistakes
- Reading innings like 190.2 as 190.2 instead of 190 and two-thirds.
- Leaving out the constant, which shifts FIP off the ERA scale.
- Expecting FIP to equal ERA for one pitcher; they differ by defense and luck.
- Flipping the sign on strikeouts - they subtract from FIP because they help the pitcher.
Frequently asked questions
What is the FIP formula?
FIP = (13 x home runs + 3 x (walks + hit-by-pitch) - 2 x strikeouts) / innings pitched + a constant. The constant, near 3.10, scales FIP to match the ERA range.
Why is FIP better than ERA sometimes?
FIP removes defense and luck on balls in play, keeping only outcomes the pitcher controls. That makes it more stable and often a better predictor of future ERA.
What is the FIP constant?
A number added so that league-average FIP equals league-average ERA. It is recalculated each season and is usually around 3.10, so you can adjust it if you have the exact figure.
What is a good FIP?
Like ERA, lower is better. Under 3.00 is excellent ace territory, around 4.00 is league average, and over 4.75 is poor.
Why do strikeouts subtract in the formula?
Strikeouts prevent runs, so they lower FIP. Home runs and walks allow or invite runs, so they raise it; the weights reflect how much each matters.