Baseball At-Bats Per Home Run Calculator

AB/HR ratio, HR%, Isolated Power (ISO) & HR pace for baseball batters

1

AB/HR Ratio & Home Run Rate

Enter at-bats, home runs, and plate appearances.

2

Isolated Power (ISO)

Measures raw extra-base power: ISO = SLG − BA.

3

HR Pace Per 162 Games

Project full-season home run pace from current stats.

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⚾ Baseball Power Benchmarks

AB/HR (lower = better)

  • <10 — Elite power
  • 10–15 — Excellent
  • 15–20 — Good
  • 20–30 — Average
  • >30 — Below avg

HR% (higher = better)

  • >4% — Elite
  • 3–4% — Great
  • 2–3% — Average
  • <2% — Low power

ISO (higher = better)

  • >.250 — Elite
  • .200–.250 — Great
  • .150–.200 — Average
  • <.150 — Below avg

What is AB/HR in Baseball?

AB/HR (at-bats per home run) is one of baseball's simplest and most powerful measures of raw hitting power. It answers a direct question: on average, how many at-bats does this batter need before hitting a home run? A lower number means the batter is a more prolific home run hitter relative to how often they come to the plate.

The stat is used by scouts, analysts, and fantasy baseball players to compare power hitters across different eras and ballparks. It complements traditional counting stats like total home runs by normalizing for playing time.

All Formulas Explained

AB/HR = At Bats ÷ Home Runs
HR% = (HR ÷ PA) × 100
ISO = SLG − BA = (2B + 2×3B + 3×HR) ÷ AB
HR Pace = (HR ÷ G) × 162
Next HR (est.) = current AB/HR ratio (remaining AB needed)

Note that HR% uses Plate Appearances (PA), not at-bats, because walks, hit-by-pitches, and sacrifice flies are included. PA = AB + BB + HBP + SF. Using PA gives a more accurate picture of home run frequency across all plate appearances.

Power Benchmarks Table

StatEliteGreatAverageBelow Avg
AB/HR<1010–1515–25>25
HR%>4%3–4%2–3%<2%
ISO>.250.200–.250.150–.200<.150
HR Pace40+30–4020–30<20

How Home Run Rates Have Changed in MLB History

Home run rates in Major League Baseball have fluctuated dramatically across different eras. Understanding these shifts puts individual AB/HR ratios in historical context:

  • Dead Ball Era (1900–1919): Home runs were extremely rare. The entire NL hit fewer home runs in some seasons than a single modern slugger hits today. AB/HR ratios of 500+ were common for regular players.
  • Live Ball Era (1920–1941): After changes to the baseball itself and the banning of the spitball, Babe Ruth transformed the game. His 1927 AB/HR of 11.76 was astonishing for the time.
  • Post-War Era (1946–1960s): HR rates stabilized. A 30-HR season was considered elite; 40+ put a player in a select group.
  • Steroid Era (1990–2005): Home run rates soared. The single-season record was broken three times (McGwire 70 in 1998, 73 Bonds in 2001). League-wide HR/PA ratios climbed to all-time highs.
  • Modern Era (2015–present): A "juiced ball" controversy and launch angle revolution drove another surge. Aaron Judge hit 62 HR in 2022, setting the AL record, with an AB/HR ratio under 9.

When comparing players across eras, it is important to consider the context. An AB/HR of 18 in 1950 was far more impressive than the same ratio today.

Frequently Asked Questions

What is AB/HR in baseball?
AB/HR (at-bats per home run) measures how many at-bats a hitter averages before hitting a home run. It is calculated by dividing total at-bats by total home runs. A lower number indicates more power — elite sluggers typically register below 10. Mark McGwire's career AB/HR of ~10.61 is the all-time MLB record.
What is ISO in baseball?
ISO (Isolated Power) measures a batter's raw extra-base hit ability by removing singles from the equation. The formula is ISO = SLG − BA, or equivalently (2B + 2×3B + 3×HR) ÷ AB. An ISO above .250 is elite, .200–.250 is great, .150–.200 is average, and below .150 is below average for an MLB regular.
What is a good home run rate (HR%)?
HR% is calculated as (HR ÷ Plate Appearances) × 100. In MLB, a HR% above 4% is elite — these are your 35–45+ HR hitters in a full season. A rate of 3–4% is great, 2–3% is average for a power hitter, and below 2% represents low power output. Aaron Judge has posted HR% above 8% in his best seasons.
How is HR pace per 162 games calculated?
HR Pace = (HR ÷ Games Played) × 162. This projects a player's current home run rate across an entire 162-game MLB season. For example, a player with 20 HR in 81 games is on a 40 HR pace. It is a useful mid-season tool for comparing players who have played different numbers of games.
Who holds the best career AB/HR ratio in MLB history?
Mark McGwire holds the all-time career AB/HR record at approximately 10.61 — hitting a home run roughly once every 10–11 at-bats. Other all-time greats include Babe Ruth (~11.76), Barry Bonds (~12.92), and Jim Thome (~13.76). Among active players, Aaron Judge and Kyle Schwarber consistently post elite AB/HR ratios.