Sports & Gaming · Statistics · Descriptive Statistics
Baseball Batting Average Calculator
Calculate a baseball player's batting average (BA) from hits and at-bats using the official MLB formula.
Calculator
Formula
BA is batting average, H is the total number of hits, and AB is the total number of official at-bats. Walks, hit-by-pitches, sacrifices, and catcher's interference are not counted as at-bats.
Source: MLB Official Baseball Rules, Rule 9.22 — Batting Average (2023 edition).
How it works
Batting average is the simplest offensive statistic in baseball: divide the number of hits (H) by the number of official at-bats (AB). The result is expressed as a three-decimal number, so a player with 150 hits in 500 at-bats has a batting average of .300. Walks, hit-by-pitches, sacrifice bunts, and sacrifice flies are explicitly excluded from the at-bat count under MLB Rule 9.22.
Slugging percentage (SLG) weighs hits by their extra-base value — singles count as 1, doubles as 2, triples as 3, and home runs as 4 — and divides the total by official at-bats. On-base percentage (OBP) captures how frequently a batter reaches base, including hits, walks, and hit-by-pitches, divided by plate appearances minus sacrifice bunts and catcher's interference. OPS combines OBP and SLG into a single power-plus-contact metric.
These statistics are foundational to modern sabermetrics and Moneyball-era roster construction. A league-average BA in MLB is typically around .250–.255; an OPS above .800 is considered good, and above .900 is elite. The calculator lets you explore all of these metrics simultaneously by entering a player's season or career counting stats.
Worked example
Example: Mike Trout — hypothetical season
Suppose a player records the following: 155 Hits, 500 At-Bats, 85 Singles, 35 Doubles, 4 Triples, 31 Home Runs, 90 Walks, 8 Hit-by-Pitches, 6 Sacrifice Flies, and 604 Plate Appearances.
Step 1 — Batting Average: BA = 155 ÷ 500 = .310
Step 2 — Total Bases: TB = (85×1) + (35×2) + (4×3) + (31×4) = 85 + 70 + 12 + 124 = 291
Step 3 — Slugging Percentage: SLG = 291 ÷ 500 = .582
Step 4 — On-Base Percentage: OBP = (155 + 90 + 8) ÷ (500 + 90 + 8 + 6) = 253 ÷ 604 = .419
Step 5 — OPS: OPS = .419 + .582 = 1.001 — a historically elite season.
Limitations & notes
Batting average does not distinguish between types of hits; a bloop single counts the same as a 450-foot double. It also ignores walks entirely, making it a less complete measure of offensive contribution than OBP or OPS. The calculator requires that you enter hits and at-bats separately; if your source reports only plate appearances, you must subtract walks, HBP, sacrifice flies, and sacrifice bunts to derive official at-bats. Additionally, batting average is heavily influenced by sample size — results from fewer than 100 at-bats are highly volatile and may not reflect true talent level.
Frequently asked questions
What is a good batting average in MLB?
The modern MLB league average hovers around .250–.255. A BA of .270–.290 is considered above average, .300 or higher is excellent, and .330+ places a hitter among the elite performers in the league. Below .220 is generally considered poor for a regular starter.
Why are walks not counted as at-bats?
Under MLB Rule 9.22, a walk (base on balls) is not charged as an official at-bat because the batter did not have a fair opportunity to make a hit — the pitcher chose not to throw a hittable pitch. This distinction ensures batting average measures contact quality rather than pitcher control.
What is the difference between plate appearances and at-bats?
A plate appearance (PA) is every time a batter completes a turn at bat, regardless of outcome. An official at-bat (AB) excludes walks, hit-by-pitches, sacrifice flies, sacrifice bunts, and catcher's interference. Therefore, AB = PA minus those excluded outcomes. Most batting stats are calculated using AB, not PA.
What does OPS measure and why is it important?
OPS (On-Base Plus Slugging) adds a player's on-base percentage to their slugging percentage. It captures both the ability to get on base and the ability to hit for power in a single number. Research has shown OPS correlates strongly with runs scored, making it a more predictive offensive metric than batting average alone. An OPS above 1.000 is considered exceptional.
What is the highest batting average ever recorded in a single MLB season?
Hugh Duffy of the Boston Beaneaters hit .440 in 1894, the highest single-season BA in MLB history. In the modern era (post-1900), Ty Cobb's .420 in 1911 is the record. Rogers Hornsby's .424 in 1924 is the highest ever recorded in the National League. The last player to hit .400 or above was Ted Williams at .406 in 1941.
How does the calculator handle partial seasons or small sample sizes?
The calculator will return a mathematically correct batting average for any number of hits and at-bats you enter, including small samples. However, interpret results from fewer than 100–150 at-bats with caution — regression to the mean means that extreme averages (.150 or .400) over small samples rarely reflect a player's true talent level. Most analysts require at least 300–400 PA for a stable offensive profile.
Can I use this calculator for Little League, college, or international baseball?
Yes. The batting average formula (H ÷ AB) is universally the same across baseball organizations worldwide. However, the definition of what constitutes a sacrifice or a hit may vary slightly by league rulebook. Always confirm the counting rules used by your specific league when entering stats, as discrepancies in how at-bats are counted can affect OBP and OPS calculations.
Last updated: 2025-01-30 · Formula verified against primary sources.