On Base Percentage Calculator (OBP)

Use our on base percentage calculator to calculate OBP from hits, bases on balls, hit by pitch, at-bats, and sacrifice flies. Includes the on base percentage formula, an example OBP calculation, and tips for calculating OBP in Excel.

Hits
Total hits (H).
Bases on Balls
Total bases on balls (BB).
Hits by Pitch
Total hit by pitch (HBP).
At Bats
Total at bats (AB).
Sacrifice Flies
Total sacrifice flies (SF).
Results
On-base percentage
OBP = (H + BB + HBP) ÷ (AB + BB + HBP + SF).
OBP measures how often a batter reaches base via hits, walks, or being hit by pitch.
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What Is On Base Percentage?

On base percentage (OBP) measures how often a hitter reaches base per plate appearance using hits, walks, and hit-by-pitch.

OBP is often considered a strong indicator of offensive value because it captures reaching base in multiple ways, not just hits.

This calculator uses the standard OBP formula with hits (H), bases on balls (BB), hit by pitch (HBP), at-bats (AB), and sacrifice flies (SF).

On Base Percentage Formula

OBP is the sum of ways a player can reach base divided by the relevant plate appearance components used in the OBP definition.

On base percentage (OBP) =
OBP = (H + BB + HBP) ÷ (AB + BB + HBP + SF)

This is the common OBP formula used in baseball stats.

H
= Hits
BB
= Bases on balls (walks)
HBP
= Hit by pitch
AB
= At-bats
SF
= Sacrifice flies
Example: on base percentage calculation
H=50, BB=20, HBP=2, AB=160, SF=5 → OBP=(50+20+2)/(160+20+2+5)=72/187=0.3850

OBP is typically shown as a decimal (example: .385).

How to Calculate On Base Percentage

  1. 1

    Enter hits (H).

  2. 2

    Enter bases on balls (BB).

  3. 3

    Enter hit by pitch (HBP).

  4. 4

    Enter at-bats (AB).

Frequently Asked Questions

How do you calculate on base percentage?

Use OBP = (H + BB + HBP) ÷ (AB + BB + HBP + SF).

What is a good on base percentage?

It depends on level and era, but higher OBP generally indicates a better ability to reach base. Comparing players within the same league and season is the fairest benchmark.

What is the average on base percentage?

Averages vary by league and season. To compare fairly, look at league-average OBP for the specific level and year you’re analyzing.

How to calculate on base percentage in Excel?

Use the OBP formula with cell references. For example: =(A2+B2+C2)/(D2+B2+C2+E2) where A2=H, B2=BB, C2=HBP, D2=AB, E2=SF.

Why does OBP include sacrifice flies?

Sacrifice flies count as plate appearances where the batter made an out, so they are included in the OBP denominator in the standard definition.