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.
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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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.
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.
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.
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.
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.
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.
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.
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.