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On-Base Percentage Calculator.

Calculate baseball on-base percentage with walks, hit by pitch, and sacrifice flies entered explicitly.

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Set your values

Results update as you type.

On-base percentage: 0.382609

On-base percentage

0.000000
On-base percentage (%): 38.26087

On-base percentage (%)

0.000000
Plate appearances: 115

Plate appearances

0.000000

Results update automatically as you type.

Use Cases

Track a player's performance

Enter a player's season or career stats to see their on-base percentage, helping evaluate their ability to get on base.

Example: Enter 150 hits, 60 walks, 5 HBP, 500 at-bats, and 10 sacrifice flies to get OBP.

Compare players or teams

Use the calculator to compare OBP across different players or teams by entering their respective stats.

Example: Calculate OBP for two players and compare their on-base skills.

Frequently Asked Questions

What is on-base percentage (OBP) and how is it calculated?
On-base percentage (OBP) measures how often a batter reaches base. It is calculated as (Hits + Walks + Hit by Pitch) divided by (At-Bats + Walks + Hit by Pitch + Sacrifice Flies). This calculator uses those exact inputs to compute OBP.
Why are sacrifice flies included in the denominator?
Sacrifice flies are included in the denominator because they represent a plate appearance where the batter does not reach base, but they are not counted as an at-bat. Including them gives a more accurate measure of how often a batter reaches base per plate appearance.
Can I use this calculator for a season or just a single game?
You can use it for any period—single game, series, or full season. Simply enter the cumulative stats for that period. The calculator will compute the OBP based on the totals you provide.

Tips & Common Mistakes

Tips

  • Double-check that you are entering the correct numbers for each field, especially at-bats and sacrifice flies, as they affect the denominator.
  • Remember that OBP is a rate stat, so it is best used over a significant number of plate appearances to be meaningful.
  • Use this calculator to quickly see how a player's OBP changes if you adjust their walk or hit totals.

Common Mistakes to Avoid

  • Including sacrifice bunts in the sacrifice flies field—only sacrifice flies count.
  • Forgetting to include hit by pitch in the numerator, which would lower the OBP incorrectly.
  • Using plate appearances instead of at-bats in the denominator without adjusting for walks, HBP, and sac flies.

Last updated: August 13, 2026