On-base percentage became famous through “Moneyball”: a batter who avoids outs helps the team score, however he gets on base. An OBP above .360 is very good.
How to use the On-Base Percentage Calculator
- Hits
- Walks (bases on balls)
- Hit by pitch
- At-bats
- Sacrifice flies
Results update as you type, every field has its own unit menu, and everything is calculated in your browser.
How it works
Enter the batter’s hits, walks, hit-by-pitches, at-bats and sacrifice flies.
Inputs explained
| Field | What to enter |
|---|---|
| Hits | A number |
| Walks (bases on balls) | A number |
| Hit by pitch | A number |
| At-bats | A number |
| Sacrifice flies | A number |
What each result means
- On-base percentage = ([Hits] + [Walks (bases on balls)] + [Hit by pitch])÷([At-bats] + [Walks (bases on balls)] + [Hit by pitch] + [Sacrifice flies])
- Plate appearances counted = [At-bats] + [Walks (bases on balls)] + [Hit by pitch] + [Sacrifice flies]
Example values
How the main result changes when Hits changes and everything else stays at the example values above:
| Hits | On-base percentage |
|---|---|
| 75 | 0.25 |
| 112.5 | 0.313 |
| 150 | 0.376 |
| 187.5 | 0.438 |
| 225 | 0.501 |
| 300 | 0.626 |
Formula
OBP = (H + BB + HBP) ÷ (AB + BB + HBP + SF)
Worked example
Inputs — Hits: 150; Walks (bases on balls): 70; Hit by pitch: 5; At-bats: 520; Sacrifice flies: 4.
Results — On-base percentage = 0.376; Plate appearances counted = 599.
Key terms
- Sacrifice fly
- A fly-ball out that scores a runner.
Frequently asked questions
What is a good OBP?
Above .360 is very good; around .320 is average.
Why are sacrifice flies included?
They are plate appearances that produce outs.
Do errors count?
Reaching on an error counts as an out for OBP.
How is OBP different from batting average?
It also credits walks and hit-by-pitches.