Slugging Percentage Calculator
Calculate a baseball or softball slugging percentage from singles, doubles, triples, home runs, and at bats — SLG = total bases ÷ at bats, rounded to three decimal places.
Input
Output
SLG equals total bases (1B + 2×2B + 3×3B + 4×HR) ÷ at bats.
Guides
How slugging percentage is calculated
Slugging percentage (SLG) measures a hitter's raw power by weighting each type of hit by the number of bases it's worth, then dividing by at bats:
Total Bases = (1 × Singles) + (2 × Doubles) + (3 × Triples) + (4 × Home Runs)
SLG = Total Bases ÷ At Bats
Unlike batting average, which counts every hit the same, slugging percentage rewards extra-base hits — a home run contributes four times as much as a single. It's written to three decimal places, the same convention as batting average (.550, spoken as "five-fifty").
How to use it
Enter your singles, doubles, triples, and home runs separately — not total hits — along with at bats. The result updates as you type. If you only know total hits, subtract doubles, triples, and home runs from it first: Singles = Hits − Doubles − Triples − Home Runs.
Why singles, not hits?
Total bases only cares about how a player got on base, so the formula needs each hit type broken out. Entering total hits instead of singles would double-count extra-base hits, since a double is already both "a hit" and "two bases." Keeping the fields separate also lets the calculator catch an impossible line — more extra-base hits than total hits — before it produces a nonsense result.
What's a good slugging percentage?
In modern Major League Baseball, .500 is considered excellent, .400 is solidly above average, and .300 or below is weak. The all-time single-season record is Barry Bonds' .863 in 2001, driven by 73 home runs in 476 at bats — that combination is one of the built-in examples for this calculator. A player who never hits for extra bases tops out at a 1.000 slugging percentage (a single every at bat); one who homers every time reaches the theoretical ceiling of 4.000.
Slugging percentage vs. batting average vs. ISO
Batting average (AVG) and slugging percentage answer different questions: AVG asks "how often did you get a hit," SLG asks "how much power was in those hits." A player can have an ordinary average but an excellent slugging percentage if most of their hits go for extra bases. Subtracting AVG from SLG gives Isolated Power (ISO), a stat some analysts prefer for isolating raw power output. SLG is also one half of OPS (on-base plus slugging), the quick-reference stat that adds it to on-base percentage.
Privacy
The calculation runs entirely in your browser. Nothing is uploaded or stored.