Earned Run Average is one of baseball’s most familiar pitching metrics, expressing how many earned runs a pitcher allows per nine innings.
Use this quick calculator to convert raw game or season totals into a polished ERA figure.
Whether you are a coach analyzing staff performance, a fan crunching numbers during a broadcast, or a fantasy player scouting free agents, this tool will give you a precise answer in seconds.
Earned Run Average (ERA) Calculator
Frequently Asked Questions
What is earned run average?
ERA is the average number of earned runs a pitcher allows per nine innings pitched.
It removes fielding errors and passed balls so the number reflects only the pitcher's responsibility.
Why is ERA calculated with nine innings?
Nine innings represent a regulation baseball game.
Using this constant scales performance no matter how many innings a pitcher actually throws, making comparisons easy.
How should I enter innings pitched?
Use decimal form where one third of an inning equals 0.1 and two thirds equals 0.2.
For example, 7 and one third innings should be entered as 7.1.
Does ERA include unearned runs?
No. Unearned runs caused by errors or passed balls are excluded so that the pitcher is not penalized for defensive mistakes.
What is considered a good ERA?
In modern Major League Baseball, an ERA below 3.50 is typically viewed as above average, while anything under 2.50 is excellent.