Earned Run Average (ERA) Calculator
Calculate and analyze pitching performance with ERA and other key metrics used by coaches, scouts, and baseball analysts.
Understanding Baseball Pitching Statistics
ERA (Earned Run Average)
The average number of earned runs a pitcher allows per nine innings pitched. ERA is calculated as: (Earned Runs ÷ Innings Pitched) × 9. Lower ERA values indicate better pitching performance.
WHIP (Walks plus Hits per Inning Pitched)
Measures a pitcher's effectiveness by calculating how many baserunners they allow per inning: (Walks + Hits) ÷ Innings Pitched. Lower WHIP values (below 1.20) indicate better performance.
K/9 (Strikeouts per 9 innings)
The average number of strikeouts a pitcher records per nine innings pitched: (Strikeouts ÷ Innings Pitched) × 9. Higher K/9 rates (above 9.0) generally indicate better swing-and-miss stuff.
K/BB (Strikeout to Walk Ratio)
Measures a pitcher's control by comparing strikeouts to walks: Strikeouts ÷ Walks. Ratios above 3.0 indicate excellent command and control.
HR/9 (Home Runs per 9 innings)
The average number of home runs a pitcher allows per nine innings: (Home Runs ÷ Innings Pitched) × 9. Lower values indicate better ability to limit hard contact and keep the ball in the park.
Frequently Asked Questions
How is ERA calculated in baseball?
ERA (Earned Run Average) is calculated using the formula: (Earned Runs ÷ Innings Pitched) × 9. This gives you the average number of earned runs a pitcher would allow in a complete 9-inning game.
What's the difference between ERA and FIP?
ERA measures actual earned runs allowed, while FIP (Fielding Independent Pitching) estimates a pitcher's effectiveness based solely on outcomes they directly control (strikeouts, walks, hit-by-pitches, and home runs), removing defensive factors. FIP can be a better predictor of future performance.
What is considered a good ERA in baseball?
ERA quality generally breaks down as:
- Below 2.00: Excellent, elite level
- 2.00-3.00: Very good
- 3.00-4.00: Good, above average
- 4.00-5.00: Average
- Above 5.00: Below average
Note that ERA standards can vary based on the era, ballpark factors, and league.
How do I input partial innings correctly?
In baseball notation, partial innings are expressed as decimal values where .1 means one out and .2 means two outs. For example:
- 6.0 = 6 complete innings (18 outs)
- 6.1 = 6 innings plus 1 out (19 outs)
- 6.2 = 6 innings plus 2 outs (20 outs)
Input your innings pitched following this convention for accurate calculations.