About the ERA Calculator
This ERA calculator works out a pitcher’s earned run average — the number of earned runs they would allow over a full game — along with the other stats scouts and fantasy players check next: WHIP (walks plus hits per inning), strikeouts per nine, walks per nine and strikeout-to-walk ratio.
Innings can be typed the way box scores print them, so 6.2 means six and two-thirds innings (20 outs), not 6.2 innings. You can also change the game length to 7 innings for softball, high school or youth leagues, where ERA is scaled to a seven-inning game.
Use it for Little League and high school stat books, college and fantasy baseball analysis, or to check what a pitcher’s ERA will become after one more start.
With the default inputs, the era is 3. Change any value above to recalculate instantly.
How to use the era calculator
- 1Enter the pitcher’s earned runs allowed.
- 2Enter innings pitched as shown in the box score (e.g. 45.1 or 6.2).
- 3Add hits, walks and strikeouts for WHIP, K/9 and BB/9.
- 4Choose 7 innings per game for softball or high school, 9 for baseball.
- 5Read the ERA and compare the rate stats in the chart.
Formula and method
Earned run average scales earned runs to a full game: multiply earned runs by the number of innings in a regulation game (9 in MLB and college, 7 in softball and most high school play) and divide by innings pitched. Unearned runs — those that score because of errors or passed balls — are not included.
Innings are recorded in thirds, one per out, so box-score notation 6.2 means 6⅔ innings (20 outs). The calculator converts .1 and .2 to thirds before dividing. WHIP is walks plus hits per inning and is not scaled by game length; K/9 and BB/9 use the same scaling as ERA.
- ER
- Earned runs allowed
- IP
- Innings pitched, in true thirds (outs ÷ 3)
- H, BB, K
- Hits, walks (bases on balls) and strikeouts
Worked examples
Season line: 20 ER in 60 innings
9 × 20 ÷ 60 = 3.00 ERA. Fifty hits plus 18 walks over 60 innings is a WHIP of 1.133, and 60 strikeouts in 60 innings is 9.0 K/9.
One start: 3 ER in 6.2 innings
6.2 innings is 6⅔ (20 outs). 9 × 3 ÷ 6.667 = 4.05 ERA, and 9 baserunners ÷ 6.667 innings = a 1.35 WHIP.
Softball pitcher: 10 ER in 35 innings
With seven-inning games, ERA = 7 × 10 ÷ 35 = 2.00. The same line on a nine-inning scale would be 2.57.
Frequently asked questions
How do you calculate ERA?+
Multiply earned runs by 9 and divide by innings pitched. A pitcher who allows 30 earned runs in 90 innings has an ERA of 9 × 30 ÷ 90 = 3.00.
What does 6.2 innings pitched mean?+
It means six full innings plus two outs, or 6⅔ innings. Each inning has three outs, so .1 is one-third of an inning and .2 is two-thirds; there is no .3.
What is a good ERA?+
In modern MLB, an ERA under 3.00 is excellent, around 4.00 is roughly league average, and above 5.00 is poor. Youth and high school ERAs vary much more with competition level.
What is WHIP and what is a good WHIP?+
WHIP is walks plus hits divided by innings pitched — how many baserunners a pitcher allows per inning. Around 1.00 is elite, 1.30 is about average and above 1.50 is poor.
How is softball ERA calculated?+
Softball and many high school leagues play seven-inning games, so ERA = 7 × earned runs ÷ innings pitched. Choose 7 innings per game in the calculator.