ERA Calculator
SportsCalculate a baseball pitcher's earned run average (ERA) from earned runs and innings pitched in seconds. Free tool for players, coaches, and fantasy baseball fans.
ERA
6
Earned Runs Per Inning
0.667
What is a ERA?
The ERA Calculator computes a baseball pitcher's Earned Run Average — the number of earned runs allowed per nine innings pitched — the standard measure of a pitcher's run-prevention performance. Enter earned runs allowed and innings pitched, and get an instant ERA.
A lower ERA is better, since it means the pitcher is allowing fewer earned runs per standard 9-inning game.
How to use this ERA calculator
Enter earned runs allowed across the innings you want to include.
Enter innings pitched, remembering that the decimal portion represents thirds of an inning (6.33 for 6⅓ innings, 6.67 for 6⅔ innings), which this calculator treats as a fractional inning.
Read your ERA instantly in the result panel — remember, lower is better.
Recalculate anytime by updating either number as your season progresses.
Formula & Methodology
ERA: ERA = (Earned Runs Allowed ÷ Innings Pitched) × 9 Worked example: Earned runs allowed = 40, Innings pitched = 60 Earned runs per inning = 40 ÷ 60 = 0.667 ERA = 0.667 × 9 = 6.00 Note: For a cricket bowler's equivalent statistic, see the Bowling Average Calculator, and to track a batter's counterpart, see the Batting Average Calculator.
Frequently Asked Questions
ERA stands for Earned Run Average, a baseball statistic measuring the average number of earned runs a pitcher allows per nine innings pitched. It's the most widely used measure of a starting pitcher's run-prevention effectiveness, since it normalizes performance to a standard 9-inning game.
An earned run is a run that scores without the help of a fielding error or passed ball — runs that result from defensive mistakes are classified as unearned and excluded from ERA, so ERA reflects the pitcher's own performance rather than their team's defense.
In Major League Baseball, an ERA below 3.00 is considered excellent (ace-level), 3.00-4.00 is solid for a regular starting pitcher, and above 4.50 is generally considered below average — league-average ERA typically hovers around 4.00 but varies by season and era.
Innings pitched in baseball is tracked in thirds — 6.1 means 6 innings plus 1 out (one-third of an inning), and 6.2 means 6 innings plus 2 outs (two-thirds of an inning). This calculator treats the decimal portion as a straight fraction of an inning, so enter 6.33 for 6⅓ innings and 6.67 for 6⅔ innings for the most accurate result.
Multiplying by 9 scales the runs-per-inning rate up to a standard 9-inning game, making ERA comparable across pitchers regardless of how many innings they actually threw in a season — a pitcher who threw 50 innings and one who threw 200 innings can be compared fairly on the same 9-inning basis.
ERA measures runs allowed per 9 innings pitched (a pitcher's run-prevention rate), while [cricket bowling average](/bowling-average-calculator/) measures runs conceded per wicket taken — both are run-prevention metrics for the 'defensive' player in their sport, but they use fundamentally different denominators suited to each game's structure.
ERA can be misleading for relief pitchers who face fewer batters and often enter in favorable situations (like with two outs already) — because of this, ERA is generally considered most reliable for starting pitchers who face a full and consistent workload of innings.
ERA depends partly on the quality of the defense behind the pitcher, ballpark factors (some stadiums favor hitters), and luck on balls in play, which is why advanced metrics like FIP (Fielding Independent Pitching) were developed to isolate a pitcher's performance from these external factors.
ERA is one of the core pitching categories in most fantasy baseball formats, often weighted alongside strikeouts, WHIP, and wins — a pitcher's ERA over a small sample size (like a few starts) can fluctuate significantly, so most fantasy managers look at ERA trends over a full season rather than a handful of games.
Yes — the ERA formula (earned runs ÷ innings pitched × 9) applies at any level of baseball or softball, from youth leagues through college and professional baseball, so you can track your own or a teammate's ERA across any season.
Win totals depend heavily on run support from the pitcher's own offense and bullpen performance after they leave the game, so a pitcher can have an excellent ERA with a modest win total (or vice versa) — ERA is generally considered a more individual and reliable performance indicator than wins.
WHIP (walks plus hits per inning pitched), strikeout rate, and walk rate are commonly tracked alongside ERA for a fuller picture of a pitcher's overall effectiveness and control, since ERA alone doesn't show how a pitcher is getting (or not getting) those results.
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