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Baseball On-Base Rate from Batting Totals

Calculate OBP from hits, walks, hit-by-pitches, at-bats and sacrifice flies, with valid zero counts and reversible relationships.

Calculator inputs

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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.

Inputs and results stay in this browser tab. Bookify does not upload or store the values you enter.

With 90 hits, 30 walks, 370 at-bats, no hit-by-pitches and no sacrifice flies, the on-base rate is 120/400 = 0.300, or 30%.

OBP = (hits + walks + hit-by-pitches)/(at-bats + walks + hit-by-pitches + sacrifice flies)

Enter these known values and leave the other values blank.

Enter nonnegative whole event counts from the same player and reporting period. Hits cannot exceed official at-bats.
The denominator must be positive. A record with no qualifying appearances has no defined on-base rate.
The output is a decimal rate: 0.300 corresponds to 30%. Use official at-bats rather than replacing that input with all plate appearances.

Yes. Walks and hit-by-pitches contribute to the numerator. Zero in any individual event count is valid when the overall denominator is positive.

Bookify validates consistent hits and at-bats, a positive on-base denominator and a decimal rate from zero through one.