ERA Calculator
Calculate Earned Run Average (ERA) — the standard measure of a pitcher's effectiveness, showing average earned runs allowed per 9 innings.
Reviewed October 7, 2026 Runs in your browser — inputs are never stored
This tool provides general sports and fitness estimates for educational purposes only. It is not medical advice — consult a physician before starting or intensifying training, especially if you have a cardiovascular condition.
About the ERA Calculator
The ERA calculator works out a pitcher’s earned run average: the earned runs they would allow over nine innings. ERA = earned runs × 9 ÷ innings pitched. Unearned runs — those that score because of fielding errors — are excluded. For partial innings, one out is a third of an inning, so 6⅔ innings is entered as 6.67.
How to use it
- 1Enter earned runs allowed.
- 2Enter innings pitched (use .33 and .67 for one and two outs).
- 3Press Calculate to see the ERA.
Worked example
30 earned runs in 90 innings gives 30 × 9 ÷ 90 = 3.00 ERA.
How it works
Formula
ERA = (Earned Runs × 9) ÷ Innings Pitched
Example
30 earned runs in 90 innings = (30 × 9) ÷ 90 = 3.00 ERA
Common use cases
- Evaluating starting and relief pitchers
- Tracking youth or amateur pitching stats
- Comparing pitchers across seasons
Frequently asked questions
A:Below 3.00 is excellent; 3.00–4.00 is above average; 4.00–5.00 is average; above 5.00 is poor.
A:ERA = (Earned Runs × 9) ÷ Innings Pitched.
A:An earned run is any run that scores without the help of a defensive error or passed ball.
A:Dutch Leonard posted a 0.96 ERA in 1914 — the lowest single-season ERA in MLB history.
A:ERA includes all earned runs (including on balls in play), while FIP isolates pitcher-controlled events.
Reviewed for accuracy · Last updated October 7, 2026
Formulas follow published sports-science literature and official league definitions (Karvonen heart rate reserve, Cooper and Bruce protocols, MET compendium values, and standard baseball, cricket, and basketball statistics).
CalcWisee Editorial Team
Calculator development and formula review
CalcWisee is an independent site founded by Ayman. Every calculator is built from a published formula or official definition, tested against hand-worked examples before it goes live, and corrected promptly when a reader reports an issue to ayman@calcwisee.com.
Expertise: Financial mathematics, Health and fitness formulas, Applied mathematics, Unit conversion standards
References & sources