ERA Calculator

Use this free ERA Calculator to calculate a pitcher’s Earned Run Average from earned runs and innings pitched.

How to Use the ERA Calculator

There are only a few steps to follow when using this calculator:

• Type in the number of runs scored.
• Type in innings pitched following the baseball format (e.g. 6.1, 6.2).
• Or put in full innings and outs.
• Use the 9-inning format for a traditional ERA.
• Click Calculate ERA.
• Check the ERA and calculation in the result.

Partial innings are automatically converted to baseball value by the calculator before computing the result.

What Is ERA?

ERA stands for Earned Run Average. It measures the average number of earned runs a pitcher allows over nine innings. A lower ERA generally indicates that a pitcher has allowed fewer earned runs relative to the number of innings pitched.

The standard ERA formula is:

ERA = (Earned Runs × 9) ÷ Innings Pitched

ERA is one of the most commonly used pitching statistics in baseball. However, it should be considered in context because factors such as defense, ballparks, league environment, and competition can influence the statistic. For the official definition and formula, see the MLB Earned Run Average glossary.

How to Calculate ERA

There are two numbers that are used to calculate ERA: earned runs and innings pitched.

If, for instance, a pitcher gives up three earned runs over the course of six innings.

ERA = (3 × 9) ÷ 6

ERA = 27 ÷ 6

ERA = 4.50

The pitcher allowed 13 earned runs, compiled a 4.50 ERA in the game.

This formula can be applied to one game, multiple games, a season, or a career. Don’t use the average of the individual game ERAs when making a season or career ERA calculation.

How Baseball Innings Pitched Are Counted

The one thing that can lead to an incorrect ERA calculation is that baseball innings are not a standard decimal number.

Baseball uses outs for “partial innings”.

• A team earns 6.0 IP for 6 innings.
• 6.1 IP stands for 6 innings and 1 out
• 6.2 IP = 6 innings and 2 outs

An inning is made up of three outs and 6.1 is an inning and a third, 6.2 is an inning and a 2/3.

For example, 6⅔ innings with 3 earned runs would be considered over a pitcher that throws 3 earned runs per 6.2 IP.

ERA = (3 × 9) ÷ 6⅔

ERA = 4.05

This is the reason to not take 6.2 for 6.2 random decimal innings. Baseball-Reference also uses the standard ERA formula of earned runs per nine innings pitched (ER/9). Check its E.R.A. glossary for more statistical background.

What Does .1 and .2 Mean in Baseball?

Innings pitched is not an innings pitched statistic, the numbers after the decimal point are outs.

If the pitcher gives up one run in an inning, he is given .1 innings. Two outs = .2 innings for a pitcher.

The standard .3 inning notation doesn’t exist because there are 3 outs and the next complete inning is beginning with the pitcher.

For example:

5.1 IP = 5 innings + 1 out = 5⅓ innings

5.2 IP = 5 innings + 2 outs = 5⅔ innings

When using an ERA calculator it’s especially crucial to understand this notation as converting the ERA as an ordinary decimal can yield the wrong result.

Does the ERA ALWAYS apply to 9 innings?

The standard ERA is earned runs allowed per nine innings. The pitcher does not have to pitch a complete nine inning game for the statistic to be computed.

A pitcher allowing 2 earned runs in 5 innings has, for instance:

ERA = (2 × 9) ÷ 5 = 3.60

The nine-inning factor is just a means to compare performances with a varying number of innings.

We have also included the optional 6 inning, 7 inning and custom game length projections on our calculator. Such projections can be helpful when you are trying to determine how the same score rate equates to a specific game length, and the ERA has been standardized to nine innings.

What Is a Good ERA?

Good ERA can’t be defined in one size fits all scenarios in baseball.

ERA will depend on league, season, ballpark, level of competition, and pitcher’s role. A number which sounds good in one context may not be in another.

ERA should be used in conjunction with other pitching statistics and conditions under which the pitcher pitched.

Also look at other statistics like WHIP, strikeout rate, walk rate, FIP and ERA+ to evaluate pitching ability.

The MLB explanation of ERA also indicates that there are other factors that can impact a pitcher’s ERA, such as the defensive performance, which is why the statistic should be used with care.

ERA vs. WHIP

ERA and WHIP are different measures of pitching.

The ERA is the number of earned runs allowed for every 9 innings pitched.

WHIP is an abbreviation for walks and hits allowed per inning pitched.

ERA is about runs and WHIP is about the frequency of hits and walks to the plate.

Combining both statistics can give a more comprehensive analysis of pitchers.

ERA vs. FIP

Fielding Independent Pitching (FIP) aims to measure some pitching results that are more directly related to the pitcher’s performance, rather than all the events that affect the ERA.

ERA measures actual earned runs allowed and FIP measures things like home runs, walks, hit batters and strikeouts.

These statistics on their own don’t tell the full story. They address different questions concerning the performance of pitchers.

FAQs

Calculate Your ERA

Enter your earned runs and innings pitched above to get an instant ERA calculation. The calculator can use standard baseball partial inning notation, allowing you to get the correct answer without having to convert outs to innings by hand.

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