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Batting average and ERA calculator

For softball, slo-pitch and baseball. Type a player's numbers: the batting average, on-base percentage, slugging, OPS and ERA work out as you type. Nothing is saved, no account.

Batting

  • Batting average (AVG)–

  • On-base percentage (OBP)–

  • Slugging (SLG)–

  • OPS (on-base plus slugging)–

Pitching

5.2 means 5 innings and 2 outs.

Innings per game
  • Earned run average (ERA)–

The formulas, with an example

Batting average: hits divided by at-bats. A player with 12 hits in 40 at-bats bats .300 (12 ÷ 40). Walks, hit by pitches and sacrifices are not at-bats, so they never lower the average.

On-base percentage: hits, walks and hit by pitches, divided by at-bats plus those walks, hit by pitches and sacrifice flies. The same player, with 5 walks, 1 hit by pitch and 2 sacrifice flies, gets (12 + 5 + 1) ÷ (40 + 5 + 1 + 2) = 18 ÷ 48 = .375.

Slugging: total bases divided by at-bats. A single is 1 base, a double 2, a triple 3 and a home run 4. The 12 hits, 7 singles, 3 doubles and 2 home runs, make 7 + 6 + 8 = 21 total bases: 21 ÷ 40 = .525.

OPS: on-base percentage plus slugging, so .375 + .525 = .900 for this player. One number that counts both getting on base and hitting for power.

ERA: the earned runs a pitcher allows, scaled to a full game. An earned run is a run scored without the help of an error or a passed ball. Multiply the earned runs by the innings in a game, then divide by the innings pitched: 9 earned runs in 21 innings give 9 × 7 ÷ 21 = 3.00 over 7 innings, and 9 × 9 ÷ 21 = 3.86 over 9 innings. Each out is a third of an inning: 5.2 innings means 5 innings and 2 outs, or 5.67 in the math.

Your softball or baseball league on Notre Ligue can keep each player's hits and RBI, game after game. During the game, the softball scoreboard shows the runs and the innings, for free.

Frequently asked questions

Why is a batting average written .300?

By tradition it has three digits after the point and no zero in front: .300 means 3 hits for every 10 at-bats. 1.000 means a hit every at-bat.

Does a walk count as an at-bat?

No. Walks, hit by pitches, sacrifice flies and sacrifice bunts are not at-bats. Walks and hit by pitches do count in the on-base percentage.

7 or 9 innings for ERA?

Use the number of innings in one of your league's games: often 7 in softball and slo-pitch, 9 in baseball. The calculator shows both.

Does Notre Ligue work out these averages for my league?

No. A softball or baseball league on Notre Ligue can keep each player's hits and RBI, game after game, when the option is on. At-bats are not kept there, so neither is the batting average or the ERA.

Are my numbers saved?

No. The math runs in your browser: nothing is sent or kept. Reloading the page clears everything.