Regardless of whether you are a baseball fan or just curious about it; for measuring the value of the earned run average (pitchers’ performance), you can use our quick and simple ERA Calculator. In addition, if you would like to learn more about baseball, and its terms (pitching, innings, earned runs), feel free to read the text below.

Are you a baseball geek and would love to see more of our calculators about baseball and other sports? Then, check out the list below we prepared for you:

What is ERA – Earned Run Average

Player shoot ball

For those who are not watching baseball and aren’t familiar with the baseball terms, “era” or “earned runs average” terms don’t mean anything. So, therefore, the question arises, “what does era mean“.

ERA stands for “earned runs average” and is one of baseball’s common statistics. Further, it indicates the number of earned runs a pitcher has allowed per the number of innings (typically 9 or 7). An ERA is one of the most popular prediction and statistical tools in baseball besides evaluating pitchers.

In baseball, pitching aims to prevent runs from scoring, and earned runs average score indicates how well pitchers perform it.

However, statistics say you should never rely on ERA completely because it has many flaws. Primarily, it is flawed because so many different factors can easily affect its score. For example, while measuring the pitcher’s performance, ERA takes into account defensive mistakes but not great defensive plays. Additionally, it’s almost impossible to evaluate the ERA score of pitchers across the two different leagues, such as Major League Baseball or National League…

How does ERA work for relief pitchers?

ERA performance scoring system is not quite as effective in measuring the performance of relief pitchers, those who often pitch only fractions of an inning. Generally, relief pitchers exert all their energy on 3 outs instead of spreading it throughout a game. Therefore, ERA will show a lower score value for relief pitchers than starting pitchers.


Henry Chadwick, a statistician and writer, is considered an inventor of the ERA baseball scoring system in the mid-to-late 19th century. Before ERA, the win-loss record system was used to measure players’ performance and determine who’s the better pitcher in baseball. However, ERA became more popular in the 20th century, when relief pitchers became more prevalent.

Earned Run

An earned run is a baseball term that indicates any run that scores against a pitcher without making any error or passed balls. For instance, if a pitcher exits a game with runners on base, any earned runs scored by will instead count against him.

What is a Pitcher?

Who is considered a pitcher in baseball? Hence, pitchers are the baseball players who pitch or begin each play towards the catcher. He has the goal to retire a batter whose goal is to either touch the ball or draw a walk. By default, they wear the dress with the number 1, and most analysts consider it the most important player in defense of the baseball team.


If you look at the statistics of baseball players and try to check their performance, you will see that each comparison has those stats: WHIP and ERA score. So, what are they, and what do they indicate?

WHIP is a baseball statistic used to evaluate a pitcher’s performance by measuring how well he keeps runners off the basepaths. Generally, you can get it by adding the number of a pitcher’s walks and hits and dividing it by his total innings pitched.

On the other hand, earned run average (ERA) represents the number of earned runs a pitcher allows per 9 innings. Any run that is scored without the aid of an error or a passed ball is considered an earned run.

WHIP is more important for individual assessment, whereas ERA is more important for determining how pitchers would fit with a team. But you should never use them individually to predict a pitcher’s performance because the statistics you get are flawed and partially incorrect.

How to Calculate ERA – ERA Formula

\text{ERA calculation formula = } \frac{\text{earned runs}}{\text{innings pitched}} \times \text{game innings}


Earned runs – the number of runs scored while the pitcher was on the mound

Innings pitched – each full inning (3 outs) that the pitcher has been on the mound

Game innings – typically, this value is equal to 9. It can be lower for softball games or little league games.

Note: If you use our ERA Calculator to calculate the earned runs average ratio for a pitcher, you can enable “Advance mode”. By enabling this feature, you can set a custom “Innings in a game”, something other than default 9.

MLB ERA Leaders

Here is the list of all-time ERA leaders in MLB sports history. In addition, the list contains the top best (lowest) ERA scores since 1880.

Tim Keefe0.86
Dutch Leonard0.96
Ed Cushman1.00
Dan Casey1.00
Mordecai Brown1.04
Bob Gibson1.12
Christy Mathewson1.14
Walter Johnson1.14
Jack Pfiester1.15
Addie Joss1.16
Carl Lundgren1.17
Denny Driscoll1.21
George Bradley1.23
Cy Young1.26
Ed Walsh1.27
Walter Johnson1.27
Christy Mathewson1.28
Guy Hecker1.30
Jack Coombs1.30
All-Time ERA Leaders in MLB History

ERA Calculator – How to Use?

Do you have problems calculating pitchers’ earned runs average score using the standard formula? Therefore, if your answer is yes, we have specially designed the ERA Calculator for you. So, all you need to do is input the required parameters, and the calculator will instantly give you the ERA score.


  • Enter the number of earned runs a pitcher has allowed
  • Specify how many innings a pitcher has pitched
  • Specify how many outs a pitcher has pitched
  • For softball games or little league games and other similar sports, you can change the game innings (Enable Advanced mode)
  • ERA Calculator will return the earned run average score.

ERA Calculator – Example

Okay, let’s take an imaginary baseball player and calculate his earned runs average score using our ERA calculator in an ERA example below.

Scenario:  How to calculate the ERA score of a pitcher with 12 earned runs, 60 innings pitched, and 2 outs.


  1. Set the number of earned runs to 12
  2. Enter that a pitcher has pitched 60 innings
  3. He had 2 outs, so set that as the “outs pitched” parameter
  4. ERA Calculator calculates the score and returns 1.78, which indicates that the pitcher has performed well on the pitch


How do you calculate ERA earned run average?

To know how to calculate ERA in baseball, you should first be familiar with some terms like earned run, inning, pitching…
– Calculate the number of innings pitched
– Consider the number of earned runs and game innings
– Use the formula: ERA = (earned runs / innings pitched) x game innings

Is a 2.00 ERA good?

If a pitcher score ERA of 2.00, it is considered that he performs excellently and is placed at the top of the ranking.

What is a good ERA in baseball?

In modern baseball:
ERA < 2.00 is considered exceptional and is rare.
2.00 < ERA < 3.00 is a score achieved by the best pitchers in baseball
3.00 < ERA < 4.00 is above-average
4.00 < ERA < 5.00 is the score that the majority of pitchers have in baseball

How do you calculate ERA in high school baseball?

To calculate the pitcher ERA score for a high school baseball league, you need to:
Divide the pitcher’s earned runs by the number of innings pitched
and then multiply the product by 7

Who has the lowest ERA ever?

The lowest ERA record in a single season ever was set by Tim Keefe in 1880, who scored 0.86 ERA in 105 innings pitched for the National League’s Troy Trojans.

Is the lower ERA better?

If a pitcher scores a lower ERA, it indicates that it has allowed fewer earned runs. Therefore, the lower ERA is, the better performance is.

Who has the best ERA in MLB history?

The best ERA of all time record in MLB holds Tim Keefe with a score of 0.86.

What is ERA+?

ERA+ takes a player’s ERA and normalizes it across the entire league. Then, it looks for external factors (ballparks and opponents) and adjusts it, so a score of 100 is league average, and 150 is 50 percent better than the league average.

What is considered a bad ERA?

Any ERA above 5.00 is considered a critical and bad ERA score.