What is ERA?
ERA (Earned Run Average) measures a pitcher's effectiveness in baseball. It calculates how many earned runs a pitcher allows per 9 innings pitched. This metric helps compare pitchers' performance and is crucial for player evaluation. Lower ERA indicates better performance. Our calculator simplifies this complex calculation, providing instant results for players, coaches, and fans to assess pitching statistics accurately.
ERA Calculator
ERA Formula
ERA = (Earned Runs × 9) ÷ Innings Pitched
How to Use
1. Enter total earned runs allowed in first input
2. Enter total innings pitched in second input
3. Click Calculate button
4. View ERA result below calculator
5. Use Clear button to reset fields
Note: Enter innings with decimal (e.g., 6.2 for 6⅔ innings)
Calculation Process
1. Multiply earned runs by 9
2. Divide result by innings pitched
3. Round to two decimal places
4. Format as ERA value
Example: 4 runs in 6 innings = (4×9)/6 = 6.00 ERA
ERA Table
| Earned Runs | Innings | ERA |
|---|---|---|
| 3 | 9 | 3.00 |
| 5 | 7 | 6.43 |
| 2 | 6 | 3.00 |
ERA FAQs
What does ERA mean in baseball?
ERA stands for Earned Run Average, representing the average number of earned runs a pitcher allows per nine innings pitched. It's calculated by multiplying earned runs by 9 and dividing by innings pitched. This metric helps evaluate pitcher performance, with lower numbers indicating better effectiveness.
How is ERA different from WHIP?
While ERA measures runs allowed, WHIP (Walks plus Hits per Inning Pitched) counts base runners. ERA focuses on scoring prevention, WHIP on baserunner prevention. Both assess pitcher performance but measure different aspects of gameplay.
What's considered a good ERA?
In modern MLB, ERA below 4.00 is good, below 3.00 is excellent. Historical context matters - 3.50 ERA was excellent in high-scoring eras. Always compare ERA to league averages for accurate assessment.
How to calculate ERA for relief pitchers?
Use the same formula: (ER×9)/IP. Relief pitchers typically have fewer innings, making ERA more volatile. Small sample sizes may not reflect true ability as accurately as starters' statistics.
Does ERA include unearned runs?
No, ERA only counts earned runs. Unearned runs resulting from errors don't affect ERA. This distinction helps separate pitcher performance from defensive mistakes.
How to handle partial innings in ERA?
Convert partial innings to decimals: .1 = 0.33, .2 = 0.67. Example: 6.1 innings = 6.33 innings in calculation. This decimal system allows precise ERA computation.
Why multiply by 9 in ERA formula?
Baseball games are 9 innings long. Multiplying by 9 standardizes the metric to show projected runs per full game. This allows comparison between starters and relievers.
Can ERA be negative?
No, ERA cannot be negative. The lowest possible ERA is 0.00. In reality, sub-1.00 ERAs are extremely rare over full seasons.
How does ballpark affect ERA?
Ballpark dimensions influence ERA. Pitchers in hitter-friendly parks often have higher ERAs. Advanced metrics like ERA+ adjust for ballpark factors in evaluation.
What's ERA+ in baseball?
ERA+ adjusts a pitcher's ERA for ballpark and league factors. 100 is average, higher is better. For example, 150 ERA+ means 50% better than league average.