Basic ERA Formula
Multiply earned runs by the regulation game length, then divide by innings pitched. ERA = (earnedRuns × gameInnings) / inningsPitched
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About ERA Calculator
Turn earned runs and innings pitched into ERA for single games, season lines, and target solve mode.
BaseballSoftballMLBHigh schoolScorebookTarget ERASeason
About this calculator
What this does
Calculates Earned Run Average (ERA) for baseball and softball pitchers across single games, season totals, and target ERA scenarios. Supports regulation lengths of 6, 7, 9, or custom innings, with both standard (whole innings + outs) and scorebook notation input modes.
Who it is for
Baseball and softball players, coaches, scorekeepers, and stat enthusiasts who need to calculate ERA from game or season data. Also useful for fantasy league managers and anyone tracking pitcher performance across different league formats.
How it works
ERA is computed using the standard formula: ERA = (earned runs × game innings) / innings pitched. For partial innings, the calculator converts outs to thirds (1 out = 1/3 inning, 2 outs = 2/3 inning). Scorebook notation (5.1 = 5⅓, 5.2 = 5⅔) is parsed accordingly. Target mode solves for the number of earned runs allowed or innings needed to reach a specific ERA goal.
Limitations
ERA is a rate stat that does not account for park factors, quality of defense, bullpen support, or opponent strength. It treats all earned runs equally regardless of when they occur. FIP, xFIP, and SIERA are more predictive metrics, but ERA remains the standard for historical comparison.
Formula
Partial Innings (Whole + Outs)
Convert outs to decimal innings where each out is one-third. inningsPitched = wholeInnings + outs / 3. For example, 5.2 means 5 + 2/3 = 5.667 innings.
Scorebook Notation
Scorebook format uses .1 for one out (1/3) and .2 for two outs (2/3). 5.1 = 5⅓ innings, 5.2 = 5⅔ innings, 6.0 = 6 full innings.
Target Mode (Reverse Solve)
Given a target ERA, solve for allowable ER at current IP or required IP at current ER. runsAllowed = (targetERA × inningsPitched) / gameInnings, inningsNeeded = (earnedRuns × gameInnings) / targetERA
How it works
Step 1
Select your mode
Choose Single Game for one-start ERA, Season Total for cumulative stats, or Target ERA to solve backwards from a desired ERA to find how many runs or innings you need.
Step 2
Choose your input format
Use Basic mode to enter whole innings and then select the number of outs (0, 1, or 2) for the partial inning. Or switch to Scorebook mode and type innings in the 5.1 or 5.2 format.
Step 3
Set the regulation length
Select 6 (softball), 7 (high school doubleheader), 9 (MLB/college), or Custom for any other inning count. This sets the denominator scale for the ERA calculation.
Step 4
Enter earned runs and innings
Input the earned runs allowed and the innings pitched. For season mode, enter the cumulative totals. The calculator updates the ERA live as you adjust the fields.
Step 5
Use Target mode for reverse solving
Enter a target ERA and either your earned runs or innings pitched to find the innings needed or runs allowed to hit that target. Useful for planning season goal pacing.
Step 6
Share or save results
Use the Copy Ledger Link button to save the current calculation state as a shareable URL, or Download Section to export a formatted HTML report for your scorebook or stat sheet.
Reference ranges
MLB Elite Range
Sub-3.00 ERA is considered elite in MLB (top 10-15%). Sub-2.50 is Cy Young caliber. The all-time MLB record for a single season (min 162 IP) is 1.12 (Bob Gibson, 1968).
MLB Average Range
MLB average ERA typically falls between 3.80-4.50 in the modern era (2010s-2020s). League-wide ERA varies significantly by year due to changes in the strike zone, ball composition, and offensive environment.
College and High School
College baseball average ERA is roughly 4.50-5.50. High school averages are higher, typically 5.00-7.00, due to less consistent defense and pitching depth. Sub-3.00 is excellent at any amateur level.
Softball ERA Scale
Softball ERAs are generally lower due to shorter game lengths (7 or 6 innings) and underhand pitching. A 2.00 ERA in softball is roughly equivalent to a 3.00 ERA in baseball on a per-game basis.