GameCalc

ERA Calculator

The gold standard for pitching performance.

Earned Runs

Innings Pitched

ERA

2.25

What you entered

Earned Runs: 25Innings Pitched: 100

1
Earned runs per inning
25 / 100= 0.25
2
ERA = (earned runs / innings pitched) x 9
0.25 x 9= 2.25

Result

ERA: 2.25

ERA for common pitching lines, from a single start to a full season

ERA is (earned runs divided by innings pitched) times 9, so the same formula covers one outing and a whole year. These are the lines pitchers post most often, with the ERA each one produces.

Innings pitched	Earned runs	ERA	What that line is
6.0	1	1.50	Dominant start
60.0	15	2.25	Elite full reliever season
200.0	55	2.48	Cy Young contender season
7.0	2	2.57	Strong start
6.33	2	2.84	6.1 IP in box score notation
6.0	2	3.00	Textbook quality start
9.0	3	3.00	Complete game
180.0	60	3.00	Solid starter season
5.0	2	3.60	Average outing
200.0	90	4.05	Back of the rotation season
6.0	3	4.50	Minimum quality start

Box score notation is not decimal: .1 means one out and .2 means two outs, so 6.1 IP is 6.33 innings and 6.2 IP is 6.67 innings. Enter the thirds, not the box score figure, or the ERA comes out low. Only earned runs count, so runs that scored because of a fielding error are excluded, and league average ERA shifts from era to era, which is why a 3.00 is judged against the season it was posted in.

Earned runs per nine innings

ERA is (earned runs ÷ innings pitched) × 9 — it estimates how many runs a pitcher would give up over a complete nine-inning game, stripping out unearned runs caused by fielding errors.

What counts as a good ERA

In modern MLB, an ERA under 3.00 is excellent, 3.00–4.00 is above average, and above 5.00 is below average — though these thresholds shift across eras (the 'dead-ball era' saw sub-2.00 league averages).

Frequently asked questions

A pitcher allowed 15 earned runs in 60 innings — what's his ERA?

ERA = (15 ÷ 60) × 9 = 2.25, which is elite-level. That's roughly the territory of top Cy Young contenders in a modern MLB season.

How is ERA different from WHIP?

ERA measures runs allowed per 9 innings, while WHIP (walks + hits per inning pitched) measures baserunners allowed per inning. A pitcher can have a low WHIP but high ERA if the hits allowed tend to go for extra bases, or vice versa.

What does the '.1' mean in innings pitched like 6.1 IP?

The '.1' represents one-third of an inning (one out recorded). Baseball notation uses .1 and .2 instead of decimals — 6.1 IP means 6 full innings plus 1 out, which equals 18.33 outs or 6.333 innings in the ERA formula.