ERA Calculator

How the ERA Calculator works

Formula. ERA = (earned runs × 9) / innings pitched.

Example. 3 earned runs in 9 innings is (3 × 9) / 9 = 3.00.

Limitation. Innings are treated as a decimal. The page does not convert baseball thirds (an out is 1/3 of an inning) from the .1 and .2 notation used in box scores.