ERA Calculator
Earned run average and WHIP, reading innings the way a box score writes them.
https://calculators.nirajiitr.com/sports/era-calculator
How it works
ERA scales a pitcher's earned runs to a full nine-inning game, so pitchers with different workloads can be compared. The trap is the innings figure. Box scores record outs after the decimal point, so 6.2 innings is six innings and two outs, or 6⅔. Typing 6.2 straight into the formula gives the wrong answer, so the calculator converts it first. For seven- or six-inning formats the 9 is replaced by the game length.
ERA = 9 × earned runs ÷ innings pitched
WHIP = (walks + hits) ÷ innings pitched- earned runs
- Runs that scored without the help of an error or passed ball
- 6.1 / 6.2
- Six innings plus one or two outs
- WHIP
- Walks plus hits per inning pitched
Worked example
A starter allows 3 earned runs on 5 hits and 2 walks over 6.2 innings.
- 1Innings: 6.2 means 6 + 2/3 = 6.667
- 2ERA: 9 × 3 ÷ 6.667 = 4.05
- 3WHIP: (2 + 5) ÷ 6.667 = 1.05
A 4.05 ERA, around league average, with a solid 1.05 WHIP.
Frequently asked questions
What is a good ERA?
In recent MLB seasons league-average ERA has sat around 4.00. Under 3.00 is excellent, and under 2.50 over a full season is elite, Cy Young territory. Above 5.00 is poor for a regular. College and high-school ERAs run differently, because of aluminium bats, fielding quality and shorter games, so compare within the same level.
What is the difference between an earned and an unearned run?
The official scorer reconstructs the inning as if no errors or passed balls had happened. Runs that would have scored anyway are earned; runs that only scored because of a defensive mistake are unearned and do not count against ERA. Once an error would have ended the inning, every later run in that inning is unearned.
How do I calculate ERA for softball or Little League?
Use the regulation game length instead of 9: 7 for high-school baseball and most softball, 6 for Little League. The formula is otherwise identical. A 7-inning ERA of 2.00 is not the same as a 9-inning ERA of 2.00, so do not compare them directly.
What does WHIP tell you that ERA does not?
WHIP measures how many baserunners a pitcher allows, before defence and sequencing decide whether they score. A pitcher with a low ERA but a high WHIP has often been lucky with runners left on base and may regress. League average WHIP is about 1.30, and under 1.10 is excellent.