Free · Baseball
Fielding Independent Pitching and League Calibration
Compute FIP from home runs, walks, hit batters, strikeouts and innings, using a supplied or league-derived constant.
- Formula & worked example
- Private in your browser
- No signup
Calculator inputs
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How to use this calculator
- Enter the known values in the units shown. Results update as you type.
- Where results are editable, change one to solve backwards. Lock a value to hold it fixed.
- Use the worked example to check the method. Reset restores the starting fields.
Private by default
Inputs and results stay in this browser tab. Bookify does not upload or store the values you enter.
Formula and method
fip = 3.8000. The example uses the declared units and assumptions.
fip = ((13 * home_runs) + (3 * (walks + hbp)) - (2 * strikeouts)) / innings_pitched + FIP_constant; calculated_FIP_constant = league_ERA - (((13 * league_home_runs) + (3 * (league_walks + league_HBP)) - (2 * league_strikeouts)) / league_innings_pitched); fip_from_calculated_fip_constant = ((13 * home_runs) + (3 * (walks + hbp)) - (2 * strikeouts)) / innings_pitched + calculated_FIP_constant
Worked example
Enter these known values and leave the other values blank.
- Calculate Constant?
- No
- Home Runs
- 1
- Walks
- 2
- Hits by Pitch
- 1
- Strikeouts
- 8
- Innings Pitched
- 10
- FIP constant
- 3.2
- FIP
- 3.8
Assumptions and limitations
- FIP isolates selected pitching events and is calibrated to the league ERA scale. Use a league constant for the same competition and season; the captured default is illustrative and is not a current-year data feed. Enter innings as ordinary numeric fractions (outs/3), not baseball .1/.2 notation.
- Editable controls retain the supported captured branches; clear an unknown and supply independent known quantities. A singular or underdetermined inverse may remain incomplete.
Common questions
What assumptions apply?
FIP isolates selected pitching events and is calibrated to the league ERA scale. Use a league constant for the same competition and season; the captured default is illustrative and is not a current-year data feed. Enter innings as ordinary numeric fractions (outs/3), not baseball .1/.2 notation.
Can I solve an unknown?
Clear an editable unknown and provide enough independent quantities in the displayed units. Discrete counts must remain whole numbers.
References
Factor the three FIP linear inverse graphs so whole-number event totals are recovered by dividing the complete integer numerator once. Captured distributed1/13 and1/3 terms leave tiny decimal residues that strict isInteger correctly rejects. These are algebraic identities, not rounding or tolerance recovery; all captured inverse targets remain available. Event totals must be nonnegative whole numbers.