ERA Calculator (Baseball & Softball: 9 & 7 Innings)

Q: How do I enter 6 and 2/3 innings into the calculator?

You can enter it as 6 and 2 outs in the picker, or as the decimal 6.2 in the IP field, which our calculator converts to the precise value of 6.667 for the calculation.

Q: What's the difference between an Earned Run and an Unearned Run?

An Earned Run (ER) would have scored even without a fielding error, passed ball, or catcher's obstruction, as determined by the official scorer (OBR 9.16). Unearned Runs are those that score solely due to a defensive or scoring error.

Q: Does ERA use 9 or 7 innings?

9 innings is the standard for MLB, most NCAA, and professional leagues. 7 innings is the standard for fastpitch softball, many youth leagues (like Little League Juniors), and high school baseball in some states. Use the toggle to select your league's regulation length.

Q: Is it better to use ERA or FIP?

ERA measures actual performance including defense, while FIP (Fielding Independent Pitching) is a projection that removes the impact of defense and luck, focusing only on walks, strikeouts, and home runs. Analysts often use both. → [FIP Calculator]

Q: How can I calculate my season ERA using multiple game logs?

Use the Add Game Log feature in our calculator. Simply input the ER and I P for each appearance, and the tool will total the statistics to provide your cumulative ERA.

Q: What are common ERA benchmarks?

In MLB, an ERA below 3.00 is elite, below 4.00 is very good, and above 5.00 is usually considered poor for a starting pitcher. Benchmarks vary significantly between 9 -inning professional and 7 -inning youth/softball leagues.

Last updated: October 04, 2025

TL;DR: The definitive ERA Calculator instantly computes Earned Run Average (ERA) for 9-inning baseball (MLB, NCAA, NFHS) and 7-inning softball/youth leagues. It correctly handles partial innings, provides multi-game logging, supports inverse goal setting, and cites official scoring rules.

ERA uses earned runs (ER), not total runs, meaning the result depends entirely on the official scorer’s judgment of errors, passed balls, and inherited runners. Results round to two decimal places by default and may differ slightly based on specific league rules (e.g., OBR, NCAA, USA Softball).

Choose $9$ – or $7$ -inning mode (default is $9$ ).
Enter total Innings Pitched (IP) using either decimals (e.g., $6.2$ for $6$ and $2/3$ IP) or the innings + outs picker.
Enter total Earned Runs (ER) allowed by the pitcher.
Review the final ERA, which is rounded to two decimal places.
Export or share the results via PDF, Copy to clipboard, or a shareable link.

Earned Run Average Calculator

Compute a pitcher's ERA for games of any length.

Welcome to the most complete and rules-aware ERA Calculator available online. Whether you are a coach tracking your starter’s progress in MLB, a parent scorekeeping a 7-inning Little League game, or a fantasy analyst projecting a reliever’s performance, this tool provides instant, accurate ERA computation.

Our calculator supports the official 9-inning standard (MLB, NCAA) and the 7-inning format (Softball, Youth Leagues) and handles the complexities of decimal innings, multi-game logs, and performance projections.

The crucial distinction: ERA relies on Earned Runs (ER), which requires the official scorer to judge the impact of errors and passed balls. This calculator is an accurate computational tool, but the final official ERA is always based on the scorer’s ruling.

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How the ERA Formula Works (OBR Compliant)

The Earned Run Average (ERA) is a statistical measure of a pitcher’s effectiveness. It quantifies the number of earned runs a pitcher allows per regulation game length. It normalizes performance so that a pitcher who throws 10 innings can be compared fairly to one who throws 100 innings.

The Core ERA Formula

The standard formula for calculating ERA is:

Earned Runs (ER): The total number of runs officially charged against the pitcher (as opposed to being unearned due to errors).
Game Innings (GI): The regulation length of a full game, typically 9 (MLB, NCAA Baseball) or 7 (Softball, NCAA/NFHS in some cases, many youth leagues). Our calculator automatically adjusts GI based on your selection.
Innings Pitched (IP): The total number of innings (including fractional innings) the pitcher completed.

Entering Innings Pitched: Decimal IP vs. Outs

The most common source of error when calculating ERA manually is handling fractional innings. A full inning equals three outs.

Outs Pitched	Fractional Innings (IP)	Decimal Value (for Formula)
1 out	1/3 inning (e.g., 6.1)	0.333
2 outs	2/3 inning (e.g., 6.2)	0.667

Crucially, in scorekeeping notation, $6$ and $2/3$ innings is written as $6.2$ , not the decimal $6.667$ .

The Problem: Entering “ $6.2$ ” into a basic calculator will result in a value of $6$ and $2/10$ innings, which is incorrect for ERA.
Our Solution: Our calculator allows you to enter total Innings Pitched in the $X .1$ or $X .2$ format or via an innings + outs picker. It automatically performs the correct conversion (e.g., $6$ IP and $2$ outs $\to 6.667$ ) to the precise decimal value needed for the ERA formula.

Rounding Rules and Precision

Official league statistics (MLB, NCAA, NFHS) round ERA to two decimal places (e.g., $4.045 \to 4.05$ ). This is the default setting for our calculator. We also provide a toggle to show $1$ , $3$ , or $4$ decimal places for contexts that require higher precision (e.g., advanced research or statistical analysis).

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Earned vs. Unearned Runs: The Scorer's Ruling (OBR 9.16 & League Rules)

The calculation is only as accurate as the Earned Runs (ER) input. ERA measures pitching performance, so runs that score due to a fielding mistake are typically deemed unearned and do not count against the pitcher’s ERA.

Errors, Passed Balls, and Fielder's Choice

Citing Authority: MLB Official Baseball Rule 9.16 (Earned Runs) dictates that a run is earned if it scores without a fielding error (including catcher’s errors), passed ball, or obstruction.

The official scorer must reconstruct the inning, assuming no errors occurred, to determine if the run still would have scored. For instance, if a third out should have been made but a fielder commits a mistake, all runs scored after that point are unearned.

Scenario	Example	ER Classification
Fielding Error	A run scores after the first baseman drops a routine throw.	Unearned (The pitcher is not charged if the run scored solely due to the error.)
Passed Ball	A run scores on a passed ball (poor catch by the catcher).	Unearned (The run is charged to the catcher/defense, not the pitcher.)
Clean Hit	The runner reaches via a clean single and later scores on a double.	Earned (Pitcher is charged with the run.)

Inherited Runners Liability

The rule for inherited runners is crucial for accurately tracking a relief pitcher’s ERA:

A relief pitcher is only responsible for the runners they put on base.
If a reliever enters the game with runners on base (inherited runners), and those runners score, the runs are charged to the previous pitcher, even if the reliever allowed the hit or walk that drove them in.

This rule is consistent across MLB, NCAA, and NFHS, ensuring that a reliever is not penalized for the performance of the pitcher they replaced.

Using the ERA Calculator: Advanced Features

Our calculator goes beyond a basic formula to provide advanced utility tailored for coaches, analysts, and scorekeepers.

Standard Mode: Single Outing or Season Totals

The simplest use is entering a pitcher’s total ER and IP for the season or a single game.

9 vs 7 Innings Toggle: Always confirm the correct setting based on your league:
- 9 Innings: MLB, MiLB, most NCAA, and advanced amateur baseball.
- 7 Innings: NCAA Softball, USA Softball, most Little League/Youth, and some high school leagues.

Logs & Projections: Cumulative ERA and "What If"

Game Log Aggregation: The Add Game Log feature allows you to input $ER$ and $I P$ for multiple appearances. The calculator aggregates the totals automatically, providing your precise cumulative season ERA.
Projection Tool (“What If”): Use the projection feature to input potential $I P$ and $ER$ for the next outing. The tool instantly shows how this performance will affect the pitcher’s current season ERA—a powerful feature for target setting and assessing impact.

Inverse ERA Calculator: Target ERA → Required IP/ER

Unique to our tool, the Inverse Mode lets you input a target ERA (e.g., $3.00$ ) and a known total for $ER$ or $I P$ . It then calculates the minimum required $I P$ or the maximum allowed $ER$ to achieve that goal.

Example: If a pitcher has allowed $10$ ER and wants a $3.00$ ERA, the inverse calculator tells you they need to pitch at least $30$ IP to reach that target.

Interpreting Your ERA Result

ERA is a foundational statistic, but it should be viewed in context. League environment, park factors, and defensive quality all impact a pitcher’s ERA.

Related Pitching Metrics

While ERA is essential, other metrics offer a fuller picture of a pitcher’s contribution:

RA/9 (Runs Allowed per 9 Innings): This is calculated the same as ERA but uses all runs (earned and unearned). It can better reflect the impact of the team’s defensive performance behind the pitcher. $\to$ [RA/9 Explainer]
WHIP (Walks plus Hits per Innings Pitched): Measures baserunners allowed. It’s a key indicator of traffic on the bases. $\to$ [WHIP Calculator]
FIP (Fielding Independent Pitching): Estimates ERA based only on outcomes the pitcher fully controls (Home Runs, Strikeouts, and Walks). It removes the variability of defense and luck. $\to$ [FIP Calculator]

Worked Examples & Case Studies

Scenario	Game Innings (GI)	Earned Runs (ER)	Innings Pitched (IP)	Calculation	Resulting ERA
MLB Starter	9	3	6 and 2/3 (6.667)	(3×9)/6.667	4.05
Softball Pitcher	7	1	7 (Complete Game)	(1×7)/7	1
Relief Appearance	9	0	1 and 1/3 (1.333)	(0×9)/1.333	0

FAQs: ERA Formula, Rules, and Use

What is the ERA formula?

ERA is calculated by multiplying the pitcher's total Earned Runs (ER) by the Game Innings (GI) (usually $9$ or $7$ ) and then dividing by the Innings Pitched (IP). The formula is $ERA = (ER \times GI) / IP$ .

How do I enter 6 and 2/3 innings into the calculator?

You can enter it as $6$ and $2$ outs in the picker, or as the decimal $6.2$ in the IP field, which our calculator converts to the precise value of $6.667$ for the calculation.

What's the difference between an Earned Run and an Unearned Run?

An Earned Run (ER) would have scored even without a fielding error, passed ball, or catcher's obstruction, as determined by the official scorer (OBR 9.16). Unearned Runs are those that score solely due to a defensive or scoring error.

Does ERA use 9 or 7 innings?

$9$ innings is the standard for MLB, most NCAA, and professional leagues. $7$ innings is the standard for fastpitch softball, many youth leagues (like Little League Juniors), and high school baseball in some states. Use the toggle to select your league's regulation length.

Are inherited runners included in a reliever’s ERA?

No. If a relief pitcher allows a runner to score who was already on base when they entered the game (an inherited runner), that run is charged to the previous pitcher, even if the run was earned.

Is it better to use ERA or FIP?

ERA measures actual performance including defense, while FIP (Fielding Independent Pitching) is a projection that removes the impact of defense and luck, focusing only on walks, strikeouts, and home runs. Analysts often use both. $\to$ [FIP Calculator]

Why does my calculator's ERA sometimes differ from the official statistic?

Official statistics are final and based on the official scorer's ruling for every earned run. Differences often arise from minor rounding variations or an error in classifying an unearned run.

How can I calculate my season ERA using multiple game logs?

Use the Add Game Log feature in our calculator. Simply input the $ER$ and $I P$ for each appearance, and the tool will total the statistics to provide your cumulative ERA.

What are common ERA benchmarks?

In MLB, an ERA below $3.00$ is elite, below $4.00$ is very good, and above $5.00$ is usually considered poor for a starting pitcher. Benchmarks vary significantly between $9$ -inning professional and $7$ -inning youth/softball leagues.

Can I use this calculator for runs allowed (RA/9) instead of ERA?

Yes. Simply use your total Runs Allowed (earned + unearned) in the Earned Runs (ER) input field to compute your Runs Allowed per 9 Innings (RA/9) instead of ERA.

Privacy & Disclaimer

All calculations are performed in-browser; no personal data or log entries are ever transmitted or stored on our servers, ensuring complete privacy. Use the Print Result or Copy Result buttons to easily save or share your calculation dataoption for your season logs.

This calculator is for informational and educational purposes only. Its accuracy depends on the user correctly classifying the total Earned Runs (ER) according to their league’s specific rule set (e.g., OBR, NCAA, NFHS). The calculator results are estimates and are not affiliated with or endorsed by MLB, NCAA, NFHS, Little League, or USA Softball.

Reference List

Authority Source	Rule/Manual
MLB	Official Baseball Rules (OBR), Rule 9.16 (Earned Runs)
NCAA	NCAA Baseball Statistics Manual
NFHS	NFHS Baseball Rules Book (Pitching Statistics)
Little League	Little League Scorekeeping Official Resources
USA Softball	USA Softball Rulebook (Pitching Statistics)