Quick answer
ERA equals earned runs times innings per game, divided by innings pitched. In baseball notation, 6.2 innings means 6 and two thirds (6.667), not 6.2 as a decimal. Eighteen earned runs over 45.1 innings in nine-inning ball is an ERA of 3.57. Enter your stats above and pick 9, 7, or 6 innings per game.
How to use this calculator
- Enter total earned runs allowed (not total runs if unearned runs scored).
- Enter innings pitched in baseball notation: whole innings plus .1 or .2 for outs (6.2 = 6 and 2/3).
- Select innings per game: 9 for standard baseball, 7 for softball or doubleheaders, 6 for some youth leagues.
- Read your ERA rounded to two decimals and the innings breakdown shown below the result.
- Double-check that .1 and .2 mean outs, not tenths of an inning. That is the most common mistake.
The formula, with worked examples
ERA = (earned runs x innings per game) / innings pitched. Innings pitched convert from baseball notation: take the whole number plus outs divided by 3. So 45.1 = 45 + 1/3 = 45.333 innings.
Example 1: nine-inning baseball. 18 earned runs over 45.1 innings. Convert 45.1 to 45.333. ERA = (18 x 9) / 45.333 = 162 / 45.333 = 3.57.
Example 2: seven-inning softball, same line. Same 18 runs and 45.1 innings, but innings per game is 7. ERA = (18 x 7) / 45.333 = 126 / 45.333 = 2.78. Shorter games scale ERA down for the same pitching line.
Earned vs unearned runs. An unearned run scores because of an error or passed ball that should have ended the inning. If a shortstop boots a grounder and the next batter homers, the homer may be unearned. ERA counts only earned runs. Official scorers decide; this tool assumes you enter earned runs only.
What counts as a good ERA by level (typical ranges)
| Level | Strong ERA range | Notes |
|---|---|---|
| MLB | under 3.50 | League average moves yearly; see MLB stats |
| College | 2.50 to 3.50 | Varies by conference and ball |
| High school | 2.00 to 4.00 | Competition and innings limits differ |
| Youth | 3.00 to 5.00 | Development matters more than the number |
League averages change every season. Compare to MLB's published league ERA at baseball-reference or mlb.com rather than treating one number as permanent.
Frequently asked questions
What is a good ERA?
In MLB, an ERA under 4.00 is decent, under 3.50 is strong, and under 3.00 is All-Star territory in most years. High school and college numbers run lower because competition and sample sizes differ. Always compare to league average for the same year and level.
How do I enter partial innings?
Use .1 for one out and .2 for two outs after the whole innings digit. 6.2 means six and two thirds innings (6.667). Never type 6.20 thinking it is six and a fifth. If you are unsure, convert outs to thirds: (whole x 3 + outs) / 3.
Why is my ERA infinity?
You allowed earned runs with zero outs recorded (0 innings pitched), or the innings field is empty. ERA needs a positive innings pitched denominator. Fix the innings entry or confirm the scorer credited you at least one out.
Does ERA include unearned runs?
No. Only earned runs count. If your line shows 5 runs allowed but 2 were unearned, enter 3 earned runs. Your ERA reflects pitching performance separate from defensive errors.
What is the difference between ERA and WHIP?
ERA measures earned runs per nine (or seven/six) innings. WHIP is walks plus hits per inning pitched. A pitcher can have a low WHIP but a higher ERA if hits cluster with runners on base. Use both for context.
Is a 4.50 ERA bad in high school?
It depends on the league. Many varsity pitchers sit between 2.50 and 4.50. If the team ERA is 5.00 and you are at 4.50, you are helping. Compare to teammates and opponents, not MLB.
Formula and sources
Formula: ERA = (earned runs x innings per game) / innings pitched. IP = whole innings + outs/3.
Sources:
Written by Raja Jahangir. Reviewed by Armghana Zeeshan. Last updated: June 30, 2026.