What this calculator does
Earned run average (ERA) works out a pitcher’s earned runs allowed per nine innings pitched, baseball or softball. Enter your own figures above and the answer updates as you type: nothing is fixed in the code, so the result reflects exactly the numbers you supply.
The formula this calculator evaluates is printed under the tool and explained below, so you can check the working by hand or reuse it in a spreadsheet.
The formula
FormulaERA = earned runs × 9 ÷ innings pitched
The inputs explained
| Field | What to enter |
|---|---|
| Earned runs allowed | A number. Starts at 38. |
| Innings pitched | A number. Starts at 180. |
Worked examples
Every figure in the tables below is produced by this page’s own calculator at build time, so the numbers and the tool always agree. Select any row to load that scenario.
How the answer changes with earned runs allowed
Every other input is held at the calculator’s starting values while earned runs allowed varies. Select any row to load that scenario into the calculator.
How the answer changes with earned runs allowed
| Earned runs allowed | ERA | Note |
|---|---|---|
| 19 | 0.95 | Enter innings pitched as decimal thirds, e.g. 6.33 for 6⅓ innings |
| 28.5 | 1.43 | Enter innings pitched as decimal thirds, e.g. 6.33 for 6⅓ innings |
| 38 | 1.90 | Enter innings pitched as decimal thirds, e.g. 6.33 for 6⅓ innings |
| 57 | 2.85 | Enter innings pitched as decimal thirds, e.g. 6.33 for 6⅓ innings |
| 76 | 3.80 | Enter innings pitched as decimal thirds, e.g. 6.33 for 6⅓ innings |
| 114 | 5.70 | Enter innings pitched as decimal thirds, e.g. 6.33 for 6⅓ innings |