Gross Production Average (GPA) Calculator

LAST UPDATE: September 24th, 2020


Definition – What is Gross Production Average?

GPA measures how likely a batter is to earn bases for the team. A higher GPA means the batter is more likely to earn bases.

It combines on base percentage with slugging percentage. It is used as an alternative to on base plus slugging (OBPS).

GPA gives heavier weight to the On Base component of the combined two metrics compared with On Base Plus Slugging (OBPS).

Formula – How to calculate GPA

GPA = ((1.8 x On Base Percentage) + Slugging Percentage) ÷ 4


If a batter has an On Base Percentage of 0.394 and a Slugging Percentage of 0.455, then:
GPA = ((1.8 x 0.394) + 0.455) / 4
GPA = (0.709 + 0.455) / 4
GPA = 1.164 / 4
GPA = 0.291
This batter’s GPA would be 0.291.

Sources and more resources