Slugging Percentage Calculator
Turn singles, doubles, triples and home runs into total bases and a slugging percentage.
What it does
Slugging percentage measures how much a hitter does with each swing. The official MLB glossary describes it as the total number of bases a player records per at bat, and gives the formula as one times the singles plus two times the doubles plus three times the triples plus four times the home runs, all divided by at bats.
The weighting is the whole idea. Counting every hit as one base would treat a bloop single and a home run the same, so doubles earn an extra base, triples two extra and home runs three extra. Algebraically the same number falls out as hits plus doubles plus two times triples plus three times home runs, which is the form the National Baseball Hall of Fame uses when it teaches the statistic.
Two details matter. The denominator is official at bats, and MLB is explicit that walks and hit by pitches are excluded, so a player who draws a lot of walks keeps a high slugging percentage. And the result is normally quoted to three decimal places, which the Hall of Fame lesson says is required.
The number is a power measure, not a contact measure. A hitter who goes 80 for 200 with 10 doubles and 20 home runs has a very different slugging percentage from one who goes 80 for 200 with 40 doubles, even though the batting average is the same. That is why slugging is paired with on base percentage: the first says how much, the second says how often.
This calculator works from the hit counts, so it uses the official definition rather than a season total, and it also reports the total bases and the extra bases that the power adds, which is often the more interesting number of the three.
How to use
- Enter the number of singles.
- Enter the number of doubles.
- Enter the number of triples.
- Enter the number of home runs.
- Enter the number of official at bats.
- Read the total bases and the slugging percentage, and compare it with the on base percentage of the same player.
Formula
- TB
- Total bases earned.
- AB
- Official at bats, which exclude walks and hit by pitches.
- SLG
- Slugging percentage, total bases per at bat.
- H
- Hits, which is singles plus doubles plus triples plus home runs.
The batting average uses the same denominator, so the two numbers can be compared directly. The traditional notation drops the leading zero, which is why a slugging percentage of 0.490 is usually written as .490. A number above 1.000 is possible, and a season of nothing but home runs would give a slugging percentage of 4.000.
Worked example
Example: 80 singles, 20 doubles, 4 triples and 16 home runs in 400 at bats
Defaults: the hit counts above with 400 official at bats.
- Total bases: 80 + 2 x 20 + 3 x 4 + 4 x 16 = 80 + 40 + 12 + 64 = 196.
- Slugging percentage: 196 / 400 = 0.490.
- Hits: 80 + 20 + 4 + 16 = 120.
- Extra bases beyond singles: 196 - 120 = 76.
- That is the same as saying the player hit 0.300 with a slugging percentage of 0.490.
- The tool shows 196 total bases, a slugging percentage of 0.490, 120 hits and 76 extra bases.
Reference table
| Hits | Total bases | Slugging percentage |
|---|---|---|
| 100 singles | 100 | 0.333 |
| 80 singles, 20 doubles | 120 | 0.400 |
| 60 singles, 30 doubles, 10 home runs | 160 | 0.533 |
| 40 singles, 30 doubles, 10 triples, 20 home runs | 210 | 0.700 |
Limits
- Uses official at bats, so it is not the same as dividing by plate appearances.
- Counts only the hits you enter, so a partial season or a split season has to be handled carefully.
- Says nothing about walks, which is why the on base percentage is reported next to it.
- Says nothing about when the hits came, so a strong start and a weak finish look the same.
Common mistakes
- Dividing by total plate appearances, which mixes in walks and hit by pitches.
- Counting every hit as one base, which gives the batting average instead of the slugging percentage.
- Forgetting that a triple is worth three bases and a home run four.
- Leaving off the leading zero and writing .49 instead of .490, since the figure is quoted to three decimals.
- Comparing a slugging percentage across leagues without checking that the at bat rules are the same.
Try it yourself
Quick checks. Answers sit tucked under each question.
A hitter has 70 singles, 30 doubles, 10 triples and 20 home runs in 500 at bats. What is the slugging percentage?
Total bases are 70 + 60 + 30 + 80 = 240, so the slugging percentage is 240 / 500 = 0.480.
What does 100 hits in 300 at bats look like with no extra bases?
100 singles give 100 total bases, so the slugging percentage is 100 / 300 = 0.333, the same as the batting average.
Does a walk count in the at bats?
No. MLB excludes walks and hit by pitches from the at bat count, which is one reason a hitter who walks a lot can show a slugging percentage well above his batting average.
Questions
What does slugging percentage measure?
The total number of bases a hitter earns per at bat, with a single worth one base, a double two, a triple three and a home run four. It is a measure of power.
How is it different from the batting average?
The batting average counts hits, while the slugging percentage counts bases. A hitter with the same batting average and more doubles has the higher slugging percentage.
What is a good slugging percentage?
Around 0.400 is solid, 0.500 is very good, and 0.600 or more is outstanding. The league average usually sits close to 0.400.
Why are walks excluded?
A walk is not an at bat, and MLB defines the statistic per at bat. A hitter who draws walks gets credit for it in the on base percentage instead.
Can the number be above 1.000?
Yes. Every at bat a player turns into a home run would give a slugging percentage of 4.000, so the scale runs well past 1.000 in a short season.
Why is it quoted to three decimal places?
Because the underlying ratio rarely divides exactly, and the convention in the sport and in the Hall of Fame teaching material is to round to the thousandths place.
Sources
- MLB official glossary: slugging percentage
- National Baseball Hall of Fame: pre-visit lesson on slugging percentage
- MLB official glossary: on base percentage