Slugging Percentage Calculator

About the Slugging Percentage Calculator

Batting average tells you how often a hitter gets a hit, but not what kind of hit. A bloop single and a 450-foot home run count exactly the same. Slugging percentage fixes that by weighting each hit by the number of bases it gains, so it measures a batter's power as well as their consistency. It is one of the core statistics of modern baseball and softball, and half of the popular OPS figure.

This slugging percentage calculator works out SLG from at-bats, hits, doubles, triples and home runs. It shows the total bases, the number of singles, the batting average, and isolated power (ISO), the part of slugging that comes purely from extra-base hits.

How to Use the Slugging Percentage Calculator

Enter the number of at-bats.

Enter the total number of hits, including extra-base hits.

Enter the number of doubles, triples and home runs. The calculator works out singles as the remaining hits.

How Slugging Percentage Is Worked Out

  singles      =  hits − doubles − triples − home runs
  total bases  =  singles + 2 × doubles + 3 × triples + 4 × home runs
  SLG          =  total bases ÷ at-bats
  ISO          =  SLG − batting average

Step-by-Step Example

500 at-bats, 150 hits, of which 30 doubles, 3 triples and 25 home runs.

  Singles:      150 − 30 − 3 − 25                 =  92
  Total bases:  92 + 2 × 30 + 3 × 3 + 4 × 25      =  261
  SLG:          261 ÷ 500                         =  .522
  Average:      150 ÷ 500                         =  .300
  ISO:          .522 − .300                       =  .222

What Is a Good Slugging Percentage?

The career record belongs to Babe Ruth at about .690. League averages have ranged from the mid-.300s in low-scoring eras to the mid-.400s in high-scoring ones, so compare players from the same period.

Why Slugging Is Not Really a Percentage

Despite its name, slugging percentage is an average: the average number of bases per at-bat. That is why it can exceed 1.000. A hitter who hits a double in every at-bat would slug 2.000, and the theoretical maximum, a home run every time, is 4.000. Like batting average, it is written to three decimal places without the leading zero when it is below 1.

Isolated Power

Isolated power strips out singles to show raw power. Because every hit counts at least one base in both batting average and slugging, subtracting one from the other leaves only the extra bases: one for each double, two for each triple and three for each home run, divided by at-bats. An ISO around .140 is average; .200 or more marks a genuine power hitter; .250 or more is exceptional. Two hitters with the same batting average can have very different ISOs, which is exactly the difference slugging is designed to reveal.

Slugging, OBP and OPS

Slugging percentage measures power, and on-base percentage measures how often a hitter reaches base, including walks. Adding the two gives OPS, on-base plus slugging, which is a quick and widely used summary of a hitter's overall value. An OPS of .800 is good, .900 very good and 1.000 exceptional. Analysts often prefer weighted versions that value getting on base a little more than slugging, but OPS remains the most familiar.

Using Slugging in Youth and Amateur Leagues

The same calculation works at every level. In youth and amateur baseball and softball, fields are smaller and home runs rarer or more common depending on the fences, so compare players within the same league. Keeping track of total bases through a season also helps coaches see who is driving the ball, not just making contact.

Two Hitters Compared

Consider two hitters, each with 150 hits in 500 at-bats — a .300 batting average. The first hits 140 singles, 8 doubles, 1 triple and 1 home run, for 163 total bases and a slugging percentage of .326. The second hits 92 singles, 30 doubles, 3 triples and 25 home runs, as in the example above, for 261 total bases and a .522 slugging percentage. Their batting averages are identical, yet the second hitter produced 98 more bases, which means many more runs. Slugging percentage and isolated power make that difference visible at a glance: the first hitter's ISO is just .026, the second's .222.

Power and Park Factors

Where a player hits matters. Ballparks with short fences, thin mountain air or warm weather produce more home runs and higher slugging percentages; large parks and cold, heavy air suppress them. Professional analysts adjust statistics for these park factors when comparing players. For amateur and youth leagues, fields vary even more, so compare hitters who play most of their games on the same fields.

Tracking Through a Season

Slugging percentage, like batting average, can swing sharply early in a season, when a couple of home runs in a small number of at-bats push it very high. Over a few hundred at-bats it settles into a reliable measure of a hitter's power.

Understanding Your Result

Slugging percentage is the average number of bases per at-bat.

Total bases gives the total bases and at-bats.

Hits by type shows singles, doubles, triples and home runs.

Batting average gives hits divided by at-bats.

Isolated power shows the extra bases per at-bat.

Rating describes the power level in professional terms.

When Should You Use This Calculator?

Tracking a hitter's power over a season.

Keeping team statistics for amateur or youth baseball.

Comparing hitters with similar batting averages.

Working out OPS with on-base percentage.

Checking a scorebook or stats app.

Common Mistakes

Counting a home run as one hit and forgetting its extra bases.

Dividing by plate appearances instead of at-bats.

Entering singles as hits, which double-counts extra-base hits.

Reading slugging as a true percentage.

Comparing players from very different eras or leagues.