Batting Average Calculator

Baseball batting statistics quantify a hitter’s effectiveness at the plate. The three most fundamental offensive metrics are Batting Average (BA), On-Base Percentage (OBP), and Slugging Percentage (SLG). Together they tell the complete story of a batter’s value.

Batting Average (BA):

BA = Hits (H) ÷ At Bats (AB)

At Bats exclude walks, hit-by-pitch, sacrifice flies, and sacrifice bunts. Only official plate appearances where the batter tries to get a hit count.

On-Base Percentage (OBP):

OBP = (H + BB + HBP) ÷ (AB + BB + HBP + SF)

• BB = walks (base on balls)
• HBP = hit by pitch
• SF = sacrifice flies

Slugging Percentage (SLG):

SLG = Total Bases ÷ At Bats

Total Bases = (1B × 1) + (2B × 2) + (3B × 3) + (HR × 4)

OPS (On-base Plus Slugging):

OPS = OBP + SLG

OPS is considered one of the best simple predictors of overall offensive production.

Worked example: A batter has: 162 AB, 52 H (38 singles, 9 doubles, 2 triples, 3 HR), 20 BB, 3 HBP, 2 SF

• BA = 52 ÷ 162 = .321
• OBP = (52 + 20 + 3) ÷ (162 + 20 + 3 + 2) = 75 ÷ 187 = .401
• Total Bases = (38×1) + (9×2) + (2×3) + (3×4) = 38+18+6+12 = 74
• SLG = 74 ÷ 162 = .457
• OPS = .401 + .457 = .858

MLB benchmarks:

A note on the leading dot. Baseball drops the zero: .321, not 0.321. But OPS regularly climbs past 1.000, and then the zero comes back. Barry Bonds finished 2004 at 1.422, and writing that as “.422” would be a different and far less interesting season. This calculator prints the leading digit whenever there is one.

Why OPS gets criticised even though everyone uses it. Adding OBP and SLG treats a point of each as equally valuable, and it is not: a point of on-base percentage is worth roughly 1.7 times a point of slugging. That is exactly the correction wOBA and OPS+ apply. OPS survives anyway because you can compute it in your head from a box score, and it still correlates with team run scoring at about .95. Good enough to argue with at a bar, not good enough to sign a contract on.