BABIP Calculator
Compute Batting Average on Balls In Play (BABIP) from hits, home runs, at-bats, strikeouts and sacrifice flies — the luck-and-skill stat that predicts regression.
How it works
BABIP = (H − HR) ÷ (AB − K − HR + SF)
BABIP measures how often a batter’s balls in play become hits, stripping out home runs and strikeouts — outcomes the fielders never touch. Because defense, luck and ballpark all sway where batted balls land, BABIP hovers near .300 league-wide and tends to regress toward a hitter’s own baseline. A season far above a player’s norm often signals good fortune due to fade; far below hints at bad luck poised to rebound, which is why it is a favourite tool for spotting unsustainable hot or cold streaks.
Worked example
A hitter has 150 hits, 20 home runs, 500 at-bats, 110 strikeouts and 5 sacrifice flies. Balls in play = 500 − 110 − 20 + 5 = 375. BABIP = (150 − 20) ÷ 375 = 130 ÷ 375 = .347 — high enough to expect some regression.
Sources: BABIP — Wikipedia
Frequently asked questions
What is a normal BABIP?
League-average BABIP sits close to .300 and is remarkably stable year to year. Individual hitters have their own baselines — fast, hard-hitting line-drive batters can sustain .330+, while fly-ball hitters run lower.
Why exclude home runs and strikeouts?
Strikeouts never put the ball in play, and home runs leave the field entirely, so neither is subject to fielding or batted-ball luck. BABIP isolates the outcomes where defense and chance actually decide hit-or-out.
Does BABIP measure luck or skill?
Both. Hitters influence it through contact quality and speed, but season-to-season swings are largely noise. A figure well off a player’s career mark usually regresses, which makes BABIP useful for forecasting rather than judging a full career.
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This calculator is for educational purposes. Double-check important results before acting on them.