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Baseball ERA Calculator

Instantly calculate earned run average (ERA) from earned runs and innings pitched. Enter innings as full innings plus outs or as a decimal, with the result shown to two decimal places.

Input

runs

How to enter innings pitched

IP
Partial inning (outs)

Result

Earned run average (ERA)

3.00

Earned runs

3 runs

Innings pitched

9 IP

Per 9 innings

3.00 runs

Calculation breakdown

ItemValue
Earned runs3 runs
Innings pitched (decimal)9.000 IP
Formula3 × 9 ÷ 9.000
ERA3.00

How it works

  • ERA is calculated as earned runs × 9 ÷ innings pitched. Multiplying by 9 expresses how many runs a pitcher allows on average per nine-inning game.
  • Partial innings are counted as one out equals one third of an inning. For example, pitching 5 full innings and recording 1 out in the next inning equals 5 1/3 innings (about 5.333 as a decimal).
  • You can enter innings pitched either as innings plus outs or as a decimal. When using a decimal, enter 5 1/3 as 5.333 and 6 2/3 as 6.667.
  • The resulting ERA is shown to two decimal places. A lower number means fewer runs allowed and a better performance.
  • Earned runs are runs charged to the pitcher; runs that scored due to errors are generally excluded. Enter the earned runs from the official record as-is.
  • ERA cannot be calculated for 0 innings pitched, so enter at least one out of innings pitched.