⚾ ERA Calculator
Calculate baseball pitcher's Earned Run Average (ERA) with instant results and performance analysis. Get accurate ERA calculations with support for partial innings and custom game formats.
ERA Calculation
Runs scored while pitcher was on mound
Complete innings pitched
Additional outs in partial inning
Standard innings per game
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Results
Performance Analysis
Enter earned runs and innings pitched to see performance analysis.
Calculation Details
Formula:
ERA = (Earned Runs ÷ Total Innings Pitched) × Game Innings
Total Innings = Innings Pitched + (Outs Pitched ÷ 3)
Frequently Asked Questions
ERA (Earned Run Average) is a statistic that measures a pitcher's effectiveness. It represents the average number of earned runs a pitcher allows per nine innings pitched. The lower the ERA, the better the pitcher's performance.
ERA is calculated using the formula: ERA = (Earned Runs ÷ Innings Pitched) × 9. For example, if a pitcher allows 15 earned runs in 65.67 innings, their ERA would be (15 ÷ 65.67) × 9 = 2.06.
Earned runs are runs that score due to the pitcher's performance, while unearned runs result from defensive errors. Only earned runs count toward ERA calculation.
Generally, an ERA below 2.00 is excellent, 2.00-3.00 is very good, 3.00-4.00 is above average, 4.00-5.00 is average, and above 5.00 needs improvement.
Each out counts as 1/3 of an inning. So if a pitcher throws 5 innings and 2 outs, that equals 5.67 innings (5 + 2/3).
The lowest career ERA in MLB history is 1.82, held by Ed Walsh (1904-1917). In the modern era (post-1920), Mariano Rivera holds the record at 2.21.
No, ERA cannot be negative since it's based on runs allowed and innings pitched, both of which are positive numbers.
Nine is used because it represents a complete game in professional baseball. For other leagues (softball uses 7, little league uses 6), the formula adjusts accordingly.
Disclaimer
This calculator is for educational and entertainment purposes only. The results are based on standard baseball statistical formulas but should not be used as the sole basis for professional baseball analysis. Users should combine these results with other statistical indicators and professional analysis for comprehensive evaluation.