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ERA (earned run average) calculator

Earned run average is the classic pitching stat: the earned runs a pitcher allows per nine innings. ERA = (earned runs × 9) ÷ innings pitched. Innings use the .1 = ⅓, .2 = ⅔ notation, so 180.2 means 180 and two-thirds innings.

At-bats per home run (AB/HR) calculatorAt-bats per home run shows how often a hitter goes deep: AB/HR = at-bats ÷ home runs. A lower number means more frequent power — elite sluggers sit around one homer every 10–15 at-bats.Batting average calculatorCompute a baseball or softball batting average from hits and at-bats.FIP (Fielding Independent Pitching) calculatorFIP estimates a pitcher's run prevention using only the outcomes they control — home runs, walks, hit-by-pitches and strikeouts — scaled to look like ERA: FIP = ((13·HR) + (3·(BB + HBP)) − (2·K)) ÷ IP + constant. The league constant (default 3.10) sets FIP to the same scale as league ERA. Innings use the .1 = ⅓, .2 = ⅔ notation.WAR (Wins Above Replacement) calculator — simplifiedA transparent, educational estimate of Wins Above Replacement. For a position player it builds batting runs from a wOBA-style comparison of the hitter's OBP/SLG to the league, adds baserunning and a positional adjustment, then converts runs above replacement to wins (÷ runs per win, default 10). For a pitcher it works from ERA versus the league. It is a teaching model, not official fWAR or bWAR.WHIP (walks + hits per inning pitched) calculatorWHIP measures how many baserunners a pitcher allows per inning via walks and hits: WHIP = (hits + walks) ÷ innings pitched. Lower is better — an elite WHIP is under 1.00. Innings use the .1 = ⅓, .2 = ⅔ notation.Cooper 12-Minute Run CalculatorEstimate VO₂max and your fitness category from the Cooper 12-minute run test, from the distance you covered, your age and sex.OPS (on-base plus slugging) calculatorOPS combines the two halves of hitting — getting on base and hitting for power — into one number: OPS = OBP + SLG. On-base percentage = (H + BB + HBP) ÷ (AB + BB + HBP + SF); slugging = (1B + 2·2B + 3·3B + 4·HR) ÷ AB, with singles = H − 2B − 3B − HR. It is the fastest all-round gauge of an offensive player.Slugging percentage (SLG) calculatorSlugging percentage measures a hitter's power by total bases per at-bat: SLG = (1B + 2·2B + 3·3B + 4·HR) ÷ AB. Unlike batting average, it weights extra-base hits, so a slugger who hits doubles and homers scores far higher than a singles hitter.

Enter Earned runs (ER), Innings pitched (IP, .1=⅓) and the ERA (earned run average) calculator works out ERA, Innings (decimal) straight away. For instance, with Earned runs (ER) = 27 and Innings pitched (IP, .1=⅓) = 180 it returns ERA = 1.35 and Innings (decimal) = 180.00.

How to use it

  1. Enter your values: Earned runs (ER), Innings pitched (IP, .1=⅓).
  2. Read the result instantly: ERA, Innings (decimal).

Frequently asked questions

What does the ERA (earned run average) calculator actually compute?

It takes Earned runs (ER) and Innings pitched (IP, .1=⅓) and derives ERA and Innings (decimal) from them. The calculation is live as you type, so the result updates on every change.

What information do I need to provide?

2 values: Earned runs (ER) and Innings pitched (IP, .1=⅓). Nothing else is required — no account, no file upload.

Can you show a worked example?

With Earned runs (ER) = 27 and Innings pitched (IP, .1=⅓) = 180, the calculator returns ERA = 1.35 and Innings (decimal) = 180.00. Those figures come from running this exact tool, so you can reproduce them by entering the same values.

When would I actually use this?

Running a league or a tournament: how many fixtures a format produces, how the table resolves ties, and what a team still needs to qualify.

What is the most common mistake?

Assuming tie-breaks work the same everywhere. Goal difference, head-to-head and goals scored are applied in a different order by nearly every competition, and the order decides the table.

What is the difference between the ERA (earned run average) calculator and the At-bats per home run (AB/HR) calculator?

This one returns ERA and Innings (decimal); the At-bats per home run (AB/HR) calculator returns At-bats per home run (AB/HR). That is the whole difference — open the one whose figure you need.

Is there a tool for the next step?

Batting average calculator is the closest one after this: Compute a baseball or softball batting average from hits and at-bats.

What else is worth having open alongside it?

FIP (Fielding Independent Pitching) calculator and WAR (Wins Above Replacement) calculator — simplified — they come up in the same task often enough to be worth a second tab.

Where do the figures come from, and how current are they?

Fixture counts and point totals are pure combinatorics and hold for any competition. The tie-break order is set by each governing body's own regulations — check the one you are actually in.

Further reading

All guides
ComparisonERA, FIP and WHIP: Three Answers to One QuestionERA measures what happened, FIP measures only what the pitcher controls without his fielders, WHIP measures traffic allowed. Two pitchers can swap places entirely between them — and the gap between ERA and FIP is a forecast, not a verdict.ExplainerHow a Golf Handicap Is Actually Calculated Under the World Handicap SystemBest 8 of your last 20 score differentials, averaged, and no 0.96 multiplier — that disappeared in 2020. Here is the full chain from a gross 92 to a Course Handicap of 17, with the numbers worked out.ExplainerOPS Is a Flawed Sum, and Still the Most Useful Number on the CardOPS adds two fractions with different denominators, which as arithmetic is indefensible. It survives because it tracks run scoring far better than batting average and costs nothing to compute — but it underpays on-base ability, and OPS+ does not fix that.How-toHow to Calculate Batting Average and What .300 MeansBatting average is hits divided by at-bats. Learn how to calculate it, why a .300 hitter is excellent and what counts as an at-bat in baseball.GuideThe Cooper Test: Distance Standards by Age and What They MeanRun as far as you can in twelve minutes, then read the distance against your age and sex. The same number also converts straight into an estimated VO2 max — here is the table and the formula.ComparisonBiological Age vs Chronological Age: What Each One Actually MeasuresChronological age is exact. Biological age is not one thing but three — epigenetic clocks, blood-marker scores and lifestyle quizzes — and only the first two have published validation. Here is how to tell which one you are looking at.