ERA calculator
Calculate earned run average (ERA) for MLB, college, high-school softball, or youth leagues. Enter earned runs and innings pitched—this tool understands baseball scorebook notation where .1 is one out and .2 is two outs.
FAQ for this calculator
- What is ERA in baseball?
- ERA (earned run average) is the average number of earned runs a pitcher allows per nine innings (or per your league's regulation length). Lower is better.
- What does 6.1 innings mean?
- In baseball notation, .1 means one out recorded in the partial inning (⅓ inning) and .2 means two outs (⅔ inning). So 6.1 = 6⅓ innings, not 6.1 decimal innings.
- Why pick 7 or 6 innings?
- High-school softball and many college softball leagues use 7-inning games. Youth baseball often uses 6. The formula multiplies by that regulation length so ERA stays comparable within a league.
- Are unearned runs included?
- No—only earned runs belong in ERA. Runs that score because of errors or passed balls are unearned and are excluded from this calculator by design.
How to use the ERA calculator
Earned Run Average (ERA) measures how many earned runs a pitcher allows per regulation game at their current rate. It is the standard pitching statistic in baseball and softball.
- Enter total earned runs allowed for the span you are measuring (one game, month, or season).
- Enter innings pitched using scorebook decimals: .1 = one out, .2 = two outs.
- Pick 9, 7, or 6 innings to match your league's regulation game length.
When to use this calculator
- Checking a single-start ERA after a outing.
- Comparing season-long ERA across 9-inning baseball vs 7-inning softball.
- Teaching how partial innings affect the denominator before a stats quiz.
Examples & walkthrough
- 3 ER, 6.0 IP, 9-inning game → ERA = (3 ÷ 6) × 9 = 4.50.
- 2 ER, 7.0 IP, 7-inning softball → ERA = (2 ÷ 7) × 7 = 2.00.
- 1 ER, 5.2 IP (5⅔), 9-inning → IP = 5.667 → ERA = (1 ÷ 5.667) × 9 ≈ 1.59.