Slugging Percentage in Baseball: Calculate SLG and Read a Hitter’s Power

Slugging percentage in baseball, usually shown as SLG, measures the average number of total bases a hitter earns per official at-bat. It values a double more than a single, a triple more than a double, and a home run most of all. The simplest formula is SLG = Total Bases ÷ At-Bats. A hitter with 11 total bases in 20 at-bats has a .550 slugging percentage.

Slugging percentage formula

SLG = (Singles + 2 × Doubles + 3 × Triples + 4 × Home Runs) ÷ At-Bats

This is the same as total bases divided by at-bats. The formula follows the official MLB glossary, which explains why SLG gives different values to different hit types. A walk is valuable to an offense, but it contributes zero total bases from a hit and is not added to the at-bat denominator.

A worked SLG example

Imagine a fictional hitter who records these results across 20 official at-bats:

• 3 singles: 3 × 1 = 3 total bases
• 2 doubles: 2 × 2 = 4 total bases
• 0 triples: 0 total bases
• 1 home run: 1 × 4 = 4 total bases

The hitter’s total is 3 + 4 + 4 = 11 total bases. Divide 11 by 20 to get .550 SLG. The player also has six hits in 20 at-bats, so their batting average is .300. These two numbers describe different parts of the same performance: batting average reports hits per at-bat, while SLG reflects the bases generated by those hits.

Does slugging percentage include walks or hit-by-pitches?

No. An intentional walk, ordinary walk or hit-by-pitch does not create a hit and does not add total bases for SLG. Those outcomes can affect a player’s on-base percentage (OBP), which is why analysts often look at OBP and SLG together.

Likewise, stealing second base after a single does not transform the original single into a double for slugging purposes. Total bases in SLG come from the value of the hit itself, not from later baserunning. Reaching on an error is not credited as a hit, either.

Slugging percentage versus batting average

Consider two illustrative hitters who each go 2-for-4:

• Hitter A: two singles mean 2 total bases in 4 at-bats. AVG .500; SLG .500.
• Hitter B: one double and one home run mean 6 total bases in 4 at-bats. AVG .500; SLG 1.500.

They have the same batting average for the game, but Hitter B supplied far more extra-base power. This is the main reason SLG exists as a separate statistic. One game is a small sample; the calculation is most meaningful with many at-bats.

Can slugging percentage be higher than 1.000?

Yes. Despite the word “percentage,” SLG is not capped at 1.000. Each official at-bat can produce as many as four total bases from a home run. For example, one home run in one at-bat yields a temporary 4.000 SLG. That number is mathematically possible, but it says little about long-term ability from such a tiny sample.

What counts as a good slugging percentage?

There is no single timeless benchmark. To evaluate SLG fairly, compare the hitter with players in the same league and season, and consider ballpark, playing time and the type of offensive role they fill. A power hitter’s SLG often comes from doubles and home runs; a contact hitter can be valuable in different ways while posting a lower SLG.

For up-to-date player rankings, use MLB’s slugging leaderboard rather than relying on an old threshold. A large sample of at-bats is far more reliable than a hot series or a single postseason game.

How SLG relates to OPS and the baseball slash line

The familiar slash line is AVG/OBP/SLG. When a broadcast shows .280/.350/.480, the first number is batting average, the second on-base percentage and the third slugging percentage. Baseball’s OPS stat adds OBP + SLG, so this illustrative player would have a .350 + .480 = .830 OPS. The MLB slash-line glossary explains this display.

SLG is also different from expected slugging (xSLG), a separate Statcast-style estimate that uses information about batted balls. Do not substitute xSLG for the traditional calculation above.

Frequently asked questions

Do stolen bases count toward SLG?

No. Stolen bases are a baserunning statistic. The SLG numerator counts total bases from hits only.

Is SLG the same as on-base percentage?

No. OBP emphasizes reaching base, including via walks and hit-by-pitches. SLG emphasizes the total bases produced by hits.

What if a hitter has no official at-bats?

The SLG calculation has no valid nonzero denominator. Do not report zero divided by zero as a meaningful slugging percentage.

For related baseball explainers, see our guides to the balk rule and how long an MLB game lasts.

Photo credit: EricEnfermero, Wikimedia Commons, CC BY-SA 4.0. Image resized for web display.