ERA Calculator (Earned Run Average)
By Santaji GadepatilinUpdated October 27, 2026
Earned run average shows how many earned runs a pitcher allows per nine innings — the standard measure of pitching performance.
How to use the ERA calculator
Enter earned runs, innings pitched (decimal), hits and walks. ERA and WHIP are calculated.
ERA formulas
ERA = 9 × ER ÷ IP WHIP = (H + BB) ÷ IP
Example
45 earned runs in 150 innings, 130 hits and 40 walks:
- ERA = 2.70
- WHIP = 1.13
ERA and WHIP benchmarks
| Rating | ERA | WHIP |
|---|---|---|
| Excellent | under 3.00 | under 1.10 |
| Above average | 3.00–3.75 | 1.10–1.25 |
| Average | 3.75–4.50 | 1.25–1.35 |
| Below average | 4.50–5.25 | 1.35–1.45 |
| Poor | over 5.25 | over 1.45 |
Rough guides for modern MLB; league scoring levels vary by year.
Innings notation
Innings are recorded in thirds: “6.1” means 6⅓ innings and “6.2” means 6⅔. Convert to decimals before calculating — 6.1 becomes 6.333 and 6.2 becomes 6.667.
Earned vs unearned runs
Runs that score because of fielding errors or passed balls are unearned and do not count towards ERA. Only earned runs reflect the pitcher’s performance.
Shorter games
For leagues with 7-inning games, ERA is sometimes scaled to 7 innings: ERA = 7 × ER ÷ IP. State which version you use.
FIP
Fielding Independent Pitching focuses on strikeouts, walks, hit batters and home runs, which the pitcher controls most directly. It is scaled to look like ERA and often predicts future ERA better.
Frequently asked questions
How is ERA calculated?
ERA = 9 × earned runs ÷ innings pitched — the earned runs a pitcher allows per nine innings.
How do I enter partial innings?
Each out is one third of an inning. 150⅓ innings = 150.333 and 150⅔ = 150.667. Scorebooks often write these as 150.1 and 150.2.
What is a good ERA?
In Major League Baseball, an ERA under 3.00 is excellent and around 4.00 is roughly average.
What is a good ERA?
Under about 3.50 is very good in modern professional baseball; under 3.00 is excellent.
How do I enter 6⅔ innings?
Enter 6.667, not 6.2.