What is ERA and how is it calculated?
ERA stands for Earned Run Average. It's a key statistic that measures a pitcher's effectiveness by showing the average number of earned runs they would allow over a full regulation game (typically 9 innings). The formula is: (Earned Runs × Innings per Game) ÷ Innings Pitched.
How do partial innings work (0.1 vs 0.2)?
In official baseball statistics, partial innings are recorded as outs. Using 0.1 for 1 out (1/3 inning) and 0.2 for 2 outs (2/3 inning) is a standard shorthand. Our calculator converts these decimals to fractions for an accurate calculation. You can also use the optional "Additional Outs" field if your IP is a whole number.
Why might ERA differ across sites?
Minor differences can occur due to rounding methods or incorrect handling of partial innings. Some basic calculators treat "50.2" as fifty-and-two-tenths instead of the correct fifty-and-two-thirds. QACalc.site uses the official fractional method for maximum accuracy, as per our QA standards.
Can I change innings per game?
Yes. While 9 innings is the standard for professional baseball (MLB), many leagues like high school or softball play 7-inning games. Use the "Innings per Game" dropdown to select 7, or choose "Custom" to set any value for your league's specific rules.
Do you store my data?
No. All calculations are performed 100% within your browser. We do not see, store, or transmit any data you enter. The "Share" feature stores the calculation data in your browser's URL, but it never reaches our servers.