X Fip Expected Fip Calculator
Our baseball calculator computes fip expected fip instantly. Get accurate stats with historical comparisons and benchmarks.
Reviewed by Sher, Sports Science & Nutrition Specialist
Formula
xFIP = ((13 * Expected HR) + (3 * (BB + HBP)) - (2 * K)) / IP + FIP Constant
Where Expected HR = Fly Balls * League HR/FB Rate, BB = Walks, HBP = Hit by Pitch, K = Strikeouts, IP = Innings Pitched, and FIP Constant is approximately 3.10 (calibrated so league FIP = league ERA).
Worked Examples
Example 1: Ace Pitcher Season Analysis
Problem:A starting pitcher has 200 IP, 220 K, 45 BB, 3 HBP, 180 fly balls, 18 HR allowed. League HR/FB is 10.5%. Calculate FIP and xFIP.
Solution:FIP = ((13*18) + (3*(45+3)) - (2*220)) / 200 + 3.10\nFIP = (234 + 144 - 440) / 200 + 3.10 = -62/200 + 3.10 = -0.31 + 3.10 = 2.79\nExpected HR = 180 * 0.105 = 18.9\nxFIP = ((13*18.9) + (3*48) - (2*220)) / 200 + 3.10\nxFIP = (245.7 + 144 - 440) / 200 + 3.10 = -50.3/200 + 3.10 = 2.85
Result:FIP: 2.79 | xFIP: 2.85 | Actual HR/FB: 10.0% | Expected HR: 18.9
Example 2: Unlucky Pitcher with High HR/FB
Problem:A pitcher has 150 IP, 130 K, 55 BB, 6 HBP, 160 fly balls, 28 HR allowed. League HR/FB is 10.5%. Is the HR rate sustainable?
Solution:HR/FB rate = 28/160 = 17.5% (well above league average 10.5%)\nFIP = ((13*28) + (3*(55+6)) - (2*130)) / 150 + 3.10\nFIP = (364 + 183 - 260) / 150 + 3.10 = 287/150 + 3.10 = 5.01\nExpected HR = 160 * 0.105 = 16.8\nxFIP = ((13*16.8) + (3*61) - (2*130)) / 150 + 3.10\nxFIP = (218.4 + 183 - 260) / 150 + 3.10 = 141.4/150 + 3.10 = 4.04
Result:FIP: 5.01 | xFIP: 4.04 | HR/FB 17.5% likely to regress toward 10.5%
Frequently Asked Questions
What is xFIP and how does it differ from FIP?
xFIP stands for Expected Fielding Independent Pitching and is a refinement of the FIP (Fielding Independent Pitching) statistic. While FIP uses a pitcher's actual home runs allowed, xFIP replaces the actual home run total with an expected number based on the league-average home run per fly ball rate. This adjustment is made because research has shown that pitchers have limited control over the percentage of their fly balls that become home runs. A pitcher who allows a high HR/FB rate in one season is likely experiencing bad luck and will regress toward the league average. xFIP therefore provides a more stable and predictive measure of pitcher performance than standard FIP.
References
Reviewed by Sher, Sports Science & Nutrition Specialist · Editorial policy