Slugging Percentage Calculator (SLG)

Enter a batter's At-Bats, Singles, Doubles, Triples, and Home Runs to compute their Slugging Percentage (SLG) — the standard measure of a hitter's power production. You'll see the SLG value, a performance rating, and a breakdown of how each hit type contributes to total bases. Also try the ERA Calculator (Earned Run Average).

Total plate appearances excluding walks, hit-by-pitch, and sacrifices.

Number of one-base hits.

Number of two-base hits.

Number of three-base hits.

Number of home runs hit.

Results

Slugging Percentage (SLG)

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Total Bases

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Performance Rating

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Total Hits

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Batting Average (H/AB)

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Frequently Asked Questions

What is Slugging Percentage (SLG)?

Slugging Percentage (SLG) measures a batter's hitting power by calculating the average number of bases earned per at-bat. Unlike batting average, it weights extra-base hits more heavily — doubles count 2x, triples 3x, and home runs 4x — making it a stronger indicator of offensive production. It is expressed as a decimal rather than a true percentage. See also our calculate OPS (On-Base Plus Slugging).

How is Slugging Percentage calculated?

The formula is: SLG = (1B + 2×2B + 3×3B + 4×HR) / AB. You multiply each hit type by the number of bases it earns, sum those values to get Total Bases, then divide by the number of At-Bats. For example, a player with 100 singles, 25 doubles, 3 triples, and 20 home runs in 500 at-bats has a SLG of (100 + 50 + 9 + 80) / 500 = 0.478.

What is a good Slugging Percentage in baseball?

As a general benchmark: below 0.300 is poor, 0.300–0.399 is below average, 0.400–0.449 is average, 0.450–0.499 is above average, 0.500–0.549 is great, and above 0.550 is elite. The MLB all-time single-season record is 0.863 by Barry Bonds in 2001.

What is the difference between Batting Average and Slugging Percentage?

Batting Average (BA) treats all hits equally — a single counts the same as a home run. Slugging Percentage goes further by weighting hits by the number of bases earned, so it better reflects a player's power and run-producing ability. A player can have a high BA but low SLG if they mostly hit singles, or a low BA but high SLG if they hit for power. You might also find our find Recommended Bat Length with Baseball Bat Size Calculator useful.

Can Slugging Percentage be higher than 1.000?

Mathematically, yes — a player who hit a home run in every single at-bat would have a SLG of 4.000. However, in practice SLG never reaches 1.000 over a full season. The highest ever recorded over a meaningful number of at-bats is Barry Bonds' 0.863 in 2001.

Do walks count toward Slugging Percentage?

No. Walks (and hit-by-pitches, sacrifices, etc.) are not counted as at-bats, so they do not factor into SLG at all. This is one reason On-Base Plus Slugging (OPS) exists — it combines On-Base Percentage (which includes walks) with SLG for a more complete picture of a hitter's value.

What is Isolated Power (ISO) and how does it relate to SLG?

Isolated Power (ISO) measures a batter's raw extra-base-hit power by removing singles from the equation. It is calculated as ISO = SLG − Batting Average. A high ISO indicates a player generates many extra bases, regardless of their overall hit rate. While SLG reflects total offensive production per at-bat, ISO isolates pure power hitting.

What is the MLB average Slugging Percentage?

The MLB league-average SLG has historically hovered around 0.400–0.430, though it fluctuates year to year based on era, rule changes, and offensive trends. A SLG above 0.450 is generally considered above average for a full-time player in the modern game.