How to Calculate Softball ERA

The effectiveness of a softball pitcher can be measured by a statistic called earned run average. ERA measures how many runs a pitcher gives up in the standard number of innings in a game. In other words, if the league plays nine-inning games, nine innings are used as the basis for the statistic. The ERA includes only runs that can be blamed on the pitcher, not runs that are given up because of fielding errors. For example, if an outfielder drops a fly ball that allowed the batter to get on base and the next batter drives in the runner, the run would be unearned and not count toward the ERA because the runner was on base because of an error.

Things You'll Need

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Instructions

    • 1

      Determine the number of earned runs the pitcher gave up and the number of innings pitched by the player. Each out counts as a third of an inning.

    • 2

      Divide the number of innings pitched by nine (if games are nine innings long) to calculate the equivalent number of games pitched. For example, if a pitcher pitched 99 innings, you would divide 99 by 9 to get 11—even if he pitched in 16 games.

    • 3

      Divide the number of earned runs allowed by the equivalent number of games pitched to calculate the player's ERA. In this example, if the pitcher gave up 22 earned runs, you would divide 22 by 11 to find the pitcher has an ERA of 2.00.