Out-safe innings entry
Enter full innings plus zero, one or two outs, so 5.1 and 5.2 can never be misread as decimal tenths.
ERA Calculator — Earned Run Average by Outs
Calculate a pitcher's earned run average without treating .1 or .2 innings as decimal tenths. Use a season total or add a game log, then normalize to 9, 7 or 6 innings.
Counts every out as one-third9-, 7- and 6-inning formatsSeason total and game logFormula shown
CALCULATE THE PITCHING LINE
Enter earned runs and outs—not a misleading decimal.
Record complete innings and extra outs separately. The calculator converts the line to total outs first, which makes 6.2 mean six innings plus two outs and prevents a common ERA error.
PITCHING LINE
Updates liveCount outs before applying the formula
Regulation game lengthThe multiplier used to normalize ERA
The calculation runs locally. No pitching line is stored.
DIRECT ANSWER
How is ERA calculated?
For Major League Baseball, ERA equals earned runs multiplied by 9, divided by innings pitched. Innings pitched are built from outs: one out is one-third of an inning and two outs are two-thirds. A line written as 6.2 therefore means 20 outs, not 6.2 decimal innings. For seven- or six-inning competition, replace 9 with the regulation game length used by that league.
BUILT FOR SCOREBOOK NOTATION
An earned run average calculator that handles partial innings
Most mistakes happen before the formula, when scorebook notation is mistaken for a decimal. This tool keeps outs explicit from the start.
Baseball and softball lengths
Normalize the rate to nine innings for MLB-style baseball, seven for softball, six for many youth formats, or a custom game length.
Season total or game log
Calculate one combined pitching line or add individual appearances and let the calculator sum the outs before computing ERA.
Transparent result breakdown
See earned runs, scorebook innings, total outs, the exact equation and a context note instead of one unexplained number.
FOUR INPUTS
How to calculate ERA correctly
ERA is simple after the pitching line is recorded correctly. Keep earned runs, outs and regulation game length separate.
Count earned runs only
Use the scorekeeper's earned-run total. Runs that would not have scored without an error or passed ball are generally unearned and do not enter ERA.
Convert innings to outs
Each full inning is three outs. Add zero, one or two extra outs; never divide the scorebook digit by ten.
Choose the game length
Use 9 for MLB-style baseball, 7 for many softball formats, or 6 for a league that normalizes pitching rates to six innings.
Divide after totaling appearances
For several games, add all earned runs and all outs first. Averaging each game's ERA can produce the wrong season result because appearances have different lengths.
INTERPRET WITH CONTEXT
A lower ERA is better, but league context still matters
ERA isolates earned runs, not every part of pitcher performance. Defense, scorer decisions, ballparks, competition level, league run environment and small samples can change how a number should be judged. The result is a mathematical rate, not a scouting grade or an official scoring decision.
PUBLIC REFERENCES
Official ERA and innings references
MLB supports the nine-inning definition and out-based innings record; USA Softball and Little League show why a calculator should allow other regulation game lengths.
Reviewed 31 July 2026- Major League BaseballEarned Run Average (ERA)MLB defines ERA as earned runs allowed per nine innings and gives the formula: 9 × earned runs ÷ innings pitched.
- Major League BaseballOfficial Baseball RulesThe official scoring rules count every recorded out as one-third of an inning pitched.
- USA SoftballOfficial RulebookUSA Softball publishes the current official rules, including the seven-inning regulation format used by many softball games.
- Little LeagueRegular-season schedule guidanceLittle League guidance documents six-inning and seven-inning schedules by division, supporting a selectable game-length factor.
COMMON QUESTIONS
ERA calculator questions
Direct answers about earned run average, partial innings, seven-inning games, softball, earned runs and interpreting a result.
What is ERA in baseball?
ERA means earned run average. It estimates how many earned runs a pitcher allows per regulation game length—nine innings in MLB—based on the innings the pitcher actually worked.
How do you calculate ERA in baseball?
Multiply earned runs by 9, then divide by innings pitched. Convert the pitching line to outs first so partial innings are handled as thirds rather than decimal tenths.
How do I enter 5.1 or 5.2 innings?
Enter 5 full innings and 1 extra out for 5.1, or 5 full innings and 2 extra outs for 5.2. In scorebook notation, the digit after the point counts outs.
What is the ERA for 2 earned runs in 6 innings?
In a nine-inning format, the ERA is (2 × 9) ÷ 6 = 3.00. If the pitcher also recorded two extra outs, the 6.2-inning ERA would be 2.70.
How does a 7-inning ERA calculator work?
Use the same formula but multiply earned runs by 7 instead of 9. The innings pitched denominator still counts every recorded out as one-third of an inning.
Can I use this ERA calculator for softball?
Yes. Choose 7 innings for a common regulation softball rate, or select a different length if the league's official scoring standard uses another normalization.
What is a good ERA in baseball?
Lower is better, but a good ERA depends on league, season, age group, competition, role and sample size. Compare the result with current league averages rather than using a universal cutoff.
Do unearned runs count toward ERA?
No. ERA uses earned runs assigned by the official scorer. Total runs allowed and earned runs can differ after errors, passed balls and reconstructed innings.