Find batting average on balls in play for any hitter or pitcher. Then check if the result is skill or luck.
Pick a mode, then choose hitter or pitcher. Blank optional boxes count as zero.
For a pitcher, enter the hits, home runs, strikeouts and at-bats against him. Line drive % sharpens the expected BABIP.
Already have a BABIP from a stats site? Type it like .345 and add the balls in play to see how much to trust it.
Hits on balls in play means all hits except home runs. Balls in play means at-bats minus strikeouts minus home runs plus sac flies.
For hitters, higher is better. For pitchers, lower is better. The colors in your result flip to match.
Most BABIP calculators give you one number and stop. This one tells you what the number means. It shows if a player is running hot or cold, how many hits that is worth, and what to expect next.
Tap an example to see it work. The hot hitter bats .300 on a BABIP that is hard to keep.
BABIP stands for batting average on balls in play. It asks one question: when a batter puts the ball in play, how often does it fall for a hit? Home runs are left out, since the defense cannot touch them. Strikeouts are left out too, because the ball never goes in play.
That makes BABIP a window into luck. Once the ball is hit, fielders, park and chance take over. A hard line drive can go right at a glove. A weak bloop can drop in. BABIP shows how much of a player's results came from those bounces.
The BABIP formula is:
BABIP = (H − HR) ÷ (AB − K − HR + SF)
| Term | Meaning |
|---|---|
| H − HR | Hits on balls in play |
| AB − K − HR + SF | Balls in play |
| SF | Sacrifice flies. They count because the ball is in play. |
Take a hitter with 550 at-bats, 165 hits, 20 home runs, 120 strikeouts and 5 sacrifice flies. Balls in play are 550 − 120 − 20 + 5 = 415. Hits on balls in play are 165 − 20 = 145. BABIP is 145 ÷ 415 = .349. His batting average is .300, but his BABIP is far above normal. The calculator checks this for you in seconds.
The league average BABIP in MLB is roughly .290 to .300. It has stayed in that range for decades. It ticked up in 2023 when rules limited defensive shifts. Use these bands as a guide:
For a hitter, a higher BABIP is better. For a pitcher, lower is better. The same .340 is a hot streak for one and a rough stretch for the other.
BABIP is a mix of both. These are the skill parts:
The luck part is where the ball lands. Two identical swings can end as a hit or an out. Over a small sample, that is mostly what you are seeing.
Pitcher BABIP uses the same formula, applied to balls hit against him. In 2001, researcher Voros McCracken found that pitchers have little control over it. Later work showed they have some, mostly through the quality of contact they allow, but the effect is small.
That is why a pitcher with a .250 BABIP and a 2.80 ERA is a warning sign, and a pitcher with a .340 BABIP and a 5.00 ERA may be better than he looks. To compare, use the FIP calculator, which ignores balls in play. Then check the WHIP calculator, since a high BABIP pushes WHIP up.
If BABIP is partly luck, what number should we expect? A well-known rule of thumb says expected BABIP ≈ line drive % + .120. A hitter with a 22% line drive rate would be expected near .340. A hitter at 17% would be near .290. Without a line drive rate, the calculator uses the league average of .295.
The Luck Check compares the real BABIP with the expected one. The gap, times the balls in play, gives hits above or below expectation. In our example, the hot hitter is about 23 hits above the league norm. At a normal BABIP, his average would drop from .300 to about .259. That is what the luck-adjusted average shows.
Not as many as a season gives you. Studies suggest a hitter's BABIP needs about 800 balls in play to mostly reflect skill, which is roughly two full seasons. For pitchers, it can take 2,000 or more. These are estimates, but the point is clear: half a season of BABIP is mostly noise.
The calculator turns this into a trust number. After 415 balls in play, a hitter's BABIP is only about a third skill. The projection blends the real BABIP with the expected one by that amount. For our hot hitter, it lands near .314, not .349. This is a rough regression guide, not a prediction.
Say a pitcher faces 600 at-bats. He allows 150 hits, 15 home runs, strikes out 160 and gives up 4 sacrifice flies. Balls in play are 429 and hits on balls in play are 135. His BABIP against is .315, about 20 points above the league norm. At a normal BABIP, he would have allowed about 8 fewer hits.
That is the "Unlucky pitcher" example above. His 160 strikeouts say he misses bats. Use the ERA target solver to see how many clean innings he needs to bring his ERA down, then compare it with his FIP. Pitchers like this often get better without changing anything.
BABIP only covers balls in play, so it says nothing about strikeouts or walks. A batter who strikes out a lot has fewer balls in play, and each one carries more weight. A pitcher who strikes out many hitters leaves less to chance. This is why elite strikeout pitchers can survive a high BABIP, while contact pitchers need good luck and good defense to stay afloat.
Run through this short checklist before you decide it is luck.
The results are simple, so you can check them by hand. Gap is real BABIP minus expected BABIP. Hits vs Expected is the gap times balls in play. Sample Trust is balls in play divided by balls in play plus 800 for hitters, or 2,000 for pitchers. Projected BABIP starts at the expected number and moves toward the real one by the trust amount. It is an estimate for planning, not a promise.
MLB BABIP has stayed in a narrow band for decades, even as strikeouts and home runs rose. That is one reason analysts trust it as a baseline. In college and high school, the story changes. Wood bats, metal bats, field quality and defense all matter. A college hitter with a .380 BABIP may be benefiting from soft infields and errors, not from special skill. Always ask how the rest of the league is doing.
Batting average counts home runs and strikeouts. BABIP does not. Two hitters with the same average can have very different BABIPs. A power hitter may bat .260 on a low BABIP because he strikes out a lot. A contact hitter may bat .260 on a high one. Look at both. You can work out the average with the batting average calculator, and see power in the slugging percentage calculator.
BABIP is a favorite tool for finding trades. Buy hitters with a low BABIP and a normal line drive rate, because their average should recover. Sell hitters well above .340 who lack speed. For pitchers, buy those with a high BABIP and good strikeout rates, and sell those with a very low one. Always check the sample size first.
The formula works at any level. Be careful with the benchmarks. Youth and high school games have more errors and weaker defense, so BABIPs are often much higher than in MLB. Compare a player to teammates and league peers. The luck check is still useful, since a huge gap between a hitter and his team is worth a look.
BABIP works best with other numbers. Try the OPS calculator for the full hitting picture, or browse every tool on the tools page.
What does BABIP stand for and how is it calculated?
It stands for batting average on balls in play. Use (H − HR) ÷ (AB − K − HR + SF).
What is a good BABIP?
The league average is roughly .290 to .300. For hitters, higher is better. For pitchers, lower is better.
Does BABIP include home runs?
No. Home runs and strikeouts are both left out.
Is a high BABIP always luck?
No. Speed, line drives and hard contact can keep it high. It is more likely luck in a small sample.
How many balls in play do you need?
About 800 for a hitter and 2,000 or more for a pitcher, as a rough guide.
Can I use BABIP for softball or youth baseball?
Yes. The formula is the same. Compare players to others in the same league.