What Is Slugging Percentage (SLG) in Baseball?
Slugging percentage (SLG) is total bases divided by at-bats. It measures a hitter’s power — the average number of bases they produce per at-bat — by weighting extra-base hits more heavily than singles. It’s a much better power indicator than batting average.
How slugging percentage is calculated
A single is worth one base, a double two, a triple three, and a home run four. Add those total bases up and divide by at-bats (per the MLB glossary definition). A hitter with 10 total bases in 20 at-bats slugs .500. The maximum possible is 4.000 (a home run every at-bat).
What counts as total bases
Only hits produce total bases: 1 for a single, 2 for a double, 3 for a triple, 4 for a home run. Walks, hit-by-pitches, and sacrifices don’t count — they aren’t at-bats, so they neither help nor hurt a hitter’s slugging percentage.
Worked example: same average, different power
Three hitters, each batting .400 over 20 at-bats — and three very different power profiles. This is exactly what batting average hides and slugging reveals:
| Hitter | 20-AB line | AVG | Total bases | SLG |
|---|---|---|---|---|
| Contact hitter | 8 singles in 20 AB | .400 | 8 | .400 |
| Gap hitter | 4 singles, 3 doubles, 1 triple in 20 AB | .400 | 13 | .650 |
| Power hitter | 5 singles, 3 home runs in 20 AB | .400 | 17 | .850 |
Slugging percentage calculator
Enter a hitter’s hit totals and at-bats — the calculator applies the formula above.
Enter at-bats and hits to see the slugging percentage.
What is a good slugging percentage?
At the MLB level, a rough reference:
| SLG range | Rating |
|---|---|
| .550 and up | Excellent |
| .500 – .549 | Very good |
| .400 – .499 | About average (MLB) |
| below .400 | Below average (MLB) |
SLG in youth & travel baseball
MLB reference points don’t transfer to a 10-year-old. Slugging shifts dramatically by age and level as pitching velocity and field dimensions change. The useful read is a hitter’s SLG against their own age group and level rather than a pro benchmark.
SLG vs batting average vs OPS
The three hitting rate stats answer different questions. Batting average asks “how often does contact become a hit?”, slugging asks “how much damage does each at-bat do?”, and OPS combines slugging with on-base percentage into one number:
| Stat | What it counts | What it misses |
|---|---|---|
| Batting average (AVG) | Hits ÷ at-bats — every hit worth the same | Power: a single and a home run count equally |
| Slugging percentage (SLG) | Total bases ÷ at-bats — extra-base hits weighted | Walks and hit-by-pitches (no at-bat, no credit) |
| OPS (OBP + SLG) | Getting on base and hitting for power, combined | Treats the two halves as equally important |
Is slugging percentage the same in softball?
Yes — softball uses the identical formula: total bases divided by at-bats. Typical values run differently because of field dimensions and the fastpitch or slowpitch context, but a coach reading an SLG column on a softball stat sheet is reading exactly the same math.
How GameLense calculates SLG
GameLense pulls your hits and at-bats straight from GameChanger and computes slugging the correct way — from aggregated totals across the season, not by averaging single-game rates (which quietly distorts the number). It sits alongside OPS, on-base percentage, and quality at-bats for a full picture of a hitter — and the same aggregate-first math applies on the pitching side to stats like ERA (earned run average).
Frequently asked questions
What is slugging percentage in baseball?
Slugging percentage (SLG) measures a hitter’s power by counting the average number of bases they earn per at-bat. Unlike batting average, which treats every hit the same, slugging gives more weight to extra-base hits — a double is worth twice a single, and a home run four times.
How is slugging percentage calculated?
SLG = total bases ÷ at-bats, where total bases = singles + (2 × doubles) + (3 × triples) + (4 × home runs). For example, a hitter with 10 total bases in 20 at-bats has a .500 slugging percentage.
What is a good slugging percentage?
At the MLB level, roughly .400 is around league average, .500 is very good, and .550 and up is excellent. In youth and travel baseball the numbers shift a lot by age and level, so SLG is most meaningful compared to a player’s own age group rather than a pro benchmark.
What does SLG stand for in baseball?
SLG is the standard abbreviation for slugging percentage. On a stat sheet it appears alongside AVG (batting average) and OBP (on-base percentage), and it measures how many total bases a hitter produces per at-bat.
What is the difference between slugging percentage and batting average?
Batting average counts all hits equally (hits ÷ at-bats), while slugging percentage weights hits by how many bases they produce. A player with lots of singles can have a high average but a modest slugging percentage; a power hitter with extra-base hits will have a much higher SLG.
How does slugging percentage relate to OPS?
OPS (On-base Plus Slugging) is simply on-base percentage plus slugging percentage: OPS = OBP + SLG. Slugging is the power half of that combined number.
Is a .500 slugging percentage good?
At the MLB level, yes — .500 is well above the league average of roughly .400. In youth and travel baseball, raw SLG values shift with age and field size, so a .500 SLG means something different at 10U than in high school; compare within the age group.
Is slugging percentage calculated the same way in softball?
Yes. Softball uses the identical formula — total bases divided by at-bats. Typical values differ because of field dimensions and the fastpitch or slowpitch context, but the math doesn’t change.
Can slugging percentage be higher than 1.000?
Yes. Because extra-base hits count multiple bases, SLG can exceed 1.000 — the theoretical maximum is 4.000 (a home run every at-bat). That’s also why SLG is written to three decimals but isn’t a true “percentage.”
What is the highest possible slugging percentage?
The maximum is 4.000, which would mean hitting a home run in every single at-bat. In practice even elite MLB seasons top out well below 1.000.
Related baseball stats
- OPS (On-base Plus Slugging)
- On-Base Percentage (OBP)
- Batting Average (AVG)
- Quality At-Bat (QAB)
- ERA (Earned Run Average)
See your team’s slugging in context
GameLense calculates SLG automatically from your GameChanger data and reads it in context alongside on-base percentage and OPS across your season.
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