Batting Average, OBP, SLG & OPS
Batting average, on-base percentage, slugging, OPS, isolated power and BABIP from a box-score line, using the MLB definitions.
The slash line (AVG / OBP / SLG), OPS and isolated power, BABIP, total bases and singles — from at-bats, hits, extra-base hits, walks, hit-by-pitches, sacrifice flies and strikeouts.
Example: 550 AB with 165 hits (35 doubles, 3 triples, 25 homers), 60 walks, 5 HBP and 5 sac flies: .300 / .371 / .511, OPS .882.
Three rates,
one line.
What each rate counts and divides by, why sacrifice flies are in one denominator and not the others, and what the line leaves out.
Average and slugging
Batting average is hits ÷ at-bats. Slugging percentage divides total bases by the same at-bats, where a single is one base, a double two, a triple three and a home run four — so it weighs how far each hit went. Isolated power, slugging minus average, keeps only the extra bases.
On-base percentage
OBP counts every way of reaching base the batter earned — hits, walks and hit-by-pitches — over at-bats plus those walks and HBP plus sacrifice flies. Sacrifice bunts and catcher’s interference are left out entirely, and reaching on an error is an at-bat without a hit, as MLB defines it. OPS is simply OBP + SLG.
BABIP
Batting average on balls in play takes the home runs and strikeouts out: (H − HR) ÷ (AB − SO − HR + SF). It is the share of batted balls in the field of play that fell for hits, and it moves with luck and defence as well as skill.
What the line does not settle
Rates on a few dozen at-bats swing widely; the page does not adjust for park, league or era. Inputs stay in your browser; the same anonymous usage counts as the rest of the site apply.
SOURCES
- MLB.com Glossary — standard and advanced batting and pitching statistics
Last reviewed 24 September 2026. How results are checked: How we verify.