How to Calculate a Pitcher's ERA

In 2011, Clayton Kershaw had the lowest ERA in the National League with a 2.28

The value of a pitcher is determined by how many runs he gives up per appearance. The most common way to calculate this is by earned run average, which factors how many runs the pitcher allows based on the number of innings he pitches. ERA is based on a nine-inning factor for baseball and a seven-inning factor for softball. The lower the number is, the better the pitcher has performed.

Difficulty:

Easy

Instructions

Things You'll Need

• Statistics on the Pitcher
• Pen
• Paper
• Calculator

1. Add only the number of earned runs the pitcher has surrendered. A pitcher's stats will show total runs allowed and earned runs allowed. The total runs allowed include runs that came in due to errors, which are not the fault of the pitcher.

2. Divide the pitcher's earned runs by the number of innings he has pitched. This number may include fractions since each out is considered part of an inning.

3. Multiply the result of that number by nine for baseball or seven for softball. So, if a pitcher has given up 12 runs and has pitched 12 innings, that pitcher has an ERA of 9.00. If a pitcher has given up 12 runs but has pitched 36 innings, that pitcher has an ERA of 3.00. In 2011, the best ERA belonged to Clayton Kershaw of the Los Angeles Dodgers. He pitched 233.1 innings and gave up 59 earned runs for an ERA of 2.28.

References

• Baseball Tips: Earned Run Average Calculator