Sports

ERA Calculator

Turn earned runs and innings pitched into ERA for single games, season lines, and target solve mode.

Official Record

Pitching Ledger

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Note: Enter whole innings and outs separately, or switch to scorebook mode and type 5.2 for five and two thirds. Two outs is two thirds of an inning, not 0.2.

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About this calculator

Method, formulas, and limits.

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.

Key calculations

Basic ERA Formula
Multiply earned runs by the regulation game length, then divide by innings pitched. ERA = (earnedRuns × gameInnings) / inningsPitched
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

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.

How to use it

  1. 1.Select your modeChoose 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.
  2. 2.Choose your input formatUse 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.
  3. 3.Set the regulation lengthSelect 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.
  4. 4.Enter earned runs and inningsInput 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.
  5. 5.Use Target mode for reverse solvingEnter 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.
  6. 6.Share or save resultsUse 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.

Use the outs selector in Basic mode to choose 0, 1, or 2 outs for the partial inning. Or switch to Scorebook mode and enter innings directly using scorebook notation—type 5.1 for five innings and one out, or 5.2 for five innings and two outs. The calculator handles the conversion automatically.

Yes. The formula stays the same, but the game length can be set to 6 innings (softball), 7 innings (high school doubleheaders or softball), 9 innings (MLB/college), or a custom number for any other league format. All ERA calculations scale to the regulation length you select.

It means five innings and two outs, not decimal 5.2. In scorebook notation, .1 equals one-third of an inning and .2 equals two-thirds. So 5.2 means 5 and 2/3 innings pitched. The calculator handles this correctly when Scorebook input mode is selected.

That depends on the level, league, and role, so this calculator keeps the math neutral and exact. In MLB, under 3.00 is excellent, 3.00-4.00 is above average, 4.00-5.00 is average, and above 5.00 is below average. For high school and college, the benchmarks are typically 1-2 runs higher.

Yes. Set the game length to 9 innings for the standard MLB ERA scale. Enter earned runs and innings pitched for a single start or season totals, and the calculator will produce the standard MLB ERA that matches official stat lines from any source.

Yes. Target mode shows how many runs or innings are needed for a chosen ERA. For example, if you have a 4.50 ERA through 40 IP but want to finish at 3.50, the calculator shows how few earned runs you can allow in your remaining innings to reach that goal.

Earned runs are runs that score without the benefit of an error or passed ball—they are the pitcher's responsibility under official scoring. Total runs include unearned runs that scored due to defensive errors. Only earned runs are used in ERA calculation, which is why this calculator asks for earned runs specifically.

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