Earned Run Average Calculator

Work out earned run average instantly with clear inputs, formula shown and shareable results.

About Earned Run Average Calculator

ERA is earned runs divided by innings pitched, scaled to a full game length, which is nine innings in baseball and seven in most softball codes. Scaling to game length is what makes ERA comparable, and it is why the same pitcher's ERA looks lower under a seven inning format.

Formula

Earned run average

ERA = earned runs / innings pitched x innings in a full game

Worked example

With the default values below, Earned Run Average Calculator returns Earned run average of 3.100. Change any input above and every figure here is recalculated in your browser.

Inputs used

Earned runs allowedminimum 0: 62
Innings pitchedminimum 0.1: 180
Innings in a full gameminimum 1: 9

Results

Earned run average: 3.100
Earned runs per inning: 0.3444
Equivalent over 7 innings: 2.411
Innings per earned run: 2.903

Step by step

1Values used
2Earned run average
3Earned run average= 3.100
4Earned runs per inning= 0.3444
5Equivalent over 7 innings= 2.411
6Innings per earned run= 2.903

Assumptions and limits

The result is derived only from the 3 inputs listed above. Anything not among them is not part of the calculation.
In particular, this calculator does not take inflation, tax, fees or charges or compounding frequency into account.
Figures are rounded for display to 4 decimal places, so totals built from several rounded parts can differ slightly from the unrounded arithmetic.

How these calculators are built and tested is described on the Methodology page. If a figure looks wrong, please report it.

Frequently Asked Questions

How is the Earned Run Average figure worked out?

ERA = earned runs / innings pitched x innings in a full game. ERA is earned runs divided by innings pitched, scaled to a full game length, which is nine innings in baseball and seven in most softball codes.

Why does this matter?

Scaling to game length is what makes ERA comparable, and it is why the same pitcher's ERA looks lower under a seven inning format.

What do I need to enter?

Enter earned runs allowed, innings pitched, innings in a full game. The defaults shown are a realistic worked example — swap in your own figures to get a result you can use.