On Base Percentage Calculator

Work out on base percentage instantly with clear inputs, formula shown and shareable results.

About On Base Percentage Calculator

On-base percentage is hits plus walks plus hit-by-pitch, divided by plate appearances excluding sacrifice hits and catcher's interference. OBP counts every way of avoiding an out, which is why it correlates with runs scored far better than batting average does.

Formula

On-base percentage

OBP = (hits + walks + hit by pitch) / plate appearances

Worked example

With the default values below, On Base Percentage Calculator returns On-base percentage of 0.3656. Change any input above and every figure here is recalculated in your browser.

Inputs used

Hitsminimum 0: 168
Walksminimum 0: 60
Hit by pitchminimum 0: 6
Plate appearances (excluding sacrifice hits)minimum 1: 640

Results

On-base percentage: 0.3656
Times reaching base: 234
Plate appearances ending in an out: 406
Walk rate: 9.38%

Step by step

1Values used
2On-base percentage
3On-base percentage= 0.3656
4Times reaching base= 234
5Plate appearances ending in an out= 406
6Walk rate= 9.38

Assumptions and limits

The result is derived only from the 4 inputs listed above. Anything not among them is not part of the calculation.
In particular, this calculator does not take inflation, tax, fees or charges or compounding frequency into account.
Figures are rounded for display to 4 decimal places, so totals built from several rounded parts can differ slightly from the unrounded arithmetic.

How these calculators are built and tested is described on the Methodology page. If a figure looks wrong, please report it.

Frequently Asked Questions

How is the On Base Percentage figure worked out?

OBP = (hits + walks + hit by pitch) / plate appearances. On-base percentage is hits plus walks plus hit-by-pitch, divided by plate appearances excluding sacrifice hits and catcher's interference.

Why does this matter?

OBP counts every way of avoiding an out, which is why it correlates with runs scored far better than batting average does.

What do I need to enter?

Enter hits, walks, hit by pitch, plate appearances (excluding sacrifice hits). The defaults shown are a realistic worked example — swap in your own figures to get a result you can use.