On Base Percentage Calculator (OBP)

Enter a batter's Hits (H), Walks (BB), Hit By Pitch (HBP), At Bats (AB), and Sacrifice Flies (SF) to calculate their On Base Percentage (OBP). The OBP Calculator also computes OPS when you provide Total Bases (TB), and shows a performance rating so you can benchmark any player against MLB standards. Also try the Percentage Increase Calculator.

H

Total number of hits the batter recorded.

BB

Total number of base on balls (walks) received.

HBP

Number of times the batter was hit by a pitch.

AB

Total official at bats (excludes walks, HBP, and sacrifice flies).

SF

Number of sacrifice flies — fly balls that scored a runner.

TB

Optional — provide Total Bases to also calculate OPS and Slugging Percentage.

Results

On Base Percentage (OBP)

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Performance Rating

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Slugging Percentage (SLG)

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OPS (OBP + SLG)

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Plate Appearances Used

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Results Table

Frequently Asked Questions

What is On-Base Percentage (OBP)?

On-Base Percentage (OBP) measures how frequently a batter reaches base per plate appearance. It accounts for hits, walks, and hit-by-pitches relative to total plate appearances (at bats + walks + HBP + sacrifice flies). Despite its name, OBP is technically an average rather than a true percentage. See also our Percentage Decrease Calculator.

How do you calculate OBP?

The formula is: OBP = (H + BB + HBP) / (AB + BB + HBP + SF). Add up a batter's hits, walks, and hit-by-pitches for the numerator, then divide by the sum of at bats, walks, HBP, and sacrifice flies. The result is expressed as a three-decimal figure, like .350.

What is a good OBP in baseball?

An OBP of .340 is considered average for MLB. Anything above .370 is very good, and elite hitters often post OBPs above .400. A figure below .300 is generally considered poor, while .300–.340 is below average but acceptable for some positions.

Why is OBP important in baseball?

OBP is one of the most valuable offensive statistics because getting on base is the fundamental prerequisite for scoring runs. Sabermetric research has shown OBP correlates more strongly with run production than traditional batting average, which is why it became a cornerstone of modern baseball analysis. You might also find our Doubling Time Calculator useful.

What is the difference between OBP and batting average?

Batting average (BA) only counts hits divided by at bats, completely ignoring walks and hit-by-pitches. OBP includes all three ways a batter can reach base without making an out, making it a more complete measure of offensive contribution. A player with a low BA but a high walk rate can still post a strong OBP.

What is OPS and how does it relate to OBP?

OPS stands for On-Base Plus Slugging. It is calculated by adding OBP and Slugging Percentage (Total Bases / At Bats). OPS combines a batter's ability to get on base with their ability to hit for power, providing a single number that captures overall offensive production. An OPS above .900 is considered excellent.

Does OBP include sacrifice flies?

Sacrifice flies are included in the denominator (plate appearances) of the OBP formula, but they do not count as hits in the numerator. This means a sacrifice fly lowers a batter's OBP slightly, reflecting that the plate appearance was used without the batter reaching base themselves.

Can OBP be used for softball statistics too?

Yes — the same OBP formula applies directly to softball statistics. As long as you have hits, walks, HBP, at bats, and sacrifice flies from a softball player's record, the calculation and interpretation are identical to baseball.