Slugging percentage (SLG) measures how many total bases a batter earns per at-bat, weighting extra-base hits more heavily than singles. It's one of the oldest advanced baseball statistics, dating to the late 1800s, and remains a core building block of modern metrics like OPS and wOBA.
How slugging percentage works
SLG = Total Bases ÷ At-Bats, where Total Bases = 1B + 2×2B + 3×3B + 4×HR. Unlike batting average, which treats every hit the same, slugging percentage rewards power: a home run contributes four times as much to the numerator as a single. Because the denominator (at-bats) is unchanged from batting average, SLG is always greater than or equal to AVG for the same batting line — the two are equal only if every hit is a single.
Inputs and what they mean
This calculator takes five inputs: at-bats and a breakdown of singles, doubles, triples, and home runs. At-bats excludes walks, hit-by-pitch, and sacrifice plays — only official plate appearances that can result in a hit or an out count. The hit breakdown must add up to the batter's total hits; if you only know total hits and extra-base hits, singles = total hits − doubles − triples − home runs.
Limits and edge cases
Slugging percentage requires at least one at-bat — this calculator shows a partial state until at-bats is entered. The theoretical maximum SLG is 4.000, reached only by homering in every at-bat. Because SLG ignores walks and hit-by-pitch entirely, it should not be used alone to judge overall offensive value — pair it with on-base percentage (as in OPS) for a fuller picture of a hitter's contribution.