Earned Run Average (ERA) Calculator

Pitcher Performance & ERA Studio

Turn earned runs and outs into a clearer pitching picture.

ERA dashboard

Earned runs per 9 innings2.70 ERA

0.30ER per inning

450Outs recorded

9 inningsRate basis

Compare with your reference

Reference ERA

Your ERA (2.70)

2.70

Reference (4.00)

4.00

32.5% lower than reference.

Reference is user-set, not an official league rating. Compare the same inning basis.

WHIP: add hits and walks

Supply both optional inputs to calculate baserunners per inning.

Every out can change your ERA

Next-inning simulator

Hypothetical scenario · starts from your stats

Realistic baseball stadium viewed from behind home plate

Ready for your next play

PitchPlayResult

Baseball pitcher in a windup on the mound

Simulated outs · 0/3

Current ERA2.70

Scenario ERA2.70

After 0 more outs and 0 earned runs:
45 ER / 150.0 IP (450 outs)

Illustrative play sequence, not a prediction or a scoring decision. +1 out = 1/3 inning.

Three outs make an inning3 outs = 1 inning; 9 innings = 27 outs.

Only earned runs enter ERAUnearned runs affect total runs, but not ERA.

A lower rate needs contextConsider league, park, defence, role and sample size.

Formula & worked example

ERA = ER × basis / IP

ERA = 45 × 9 / 150 = 2.70

Equivalent (using outs): 45 × 27 / 450 = 2.70

Baseball notation after the dot counts outs, not tenths. A 7- or 6-inning basis is an alternative normalization, not standard MLB ERA.

Frequently asked questions

What does 150.1 IP mean?

It means 150 completed innings plus one out: 150 + 1/3 innings, or 451 outs. A .2 suffix means two additional outs. Values such as 150.3 or 150.5 are not valid baseball IP notation.

What if no outs are recorded?

With no outs there is no innings denominator: 0 earned runs over 0 innings is undefined, and positive earned runs over 0 innings gives an unbounded rate. The display uses an em dash or infinity rather than inventing a zero ERA.

Can ERA alone rank a pitcher?

No. ERA depends on context and sample size. The reference comparison is a user-selected rate comparison, not an official ranking, award prediction or league-adjusted ERA+.

Why can’t WHIP be inferred from ERA?

WHIP uses hits and walks, which are different counts from earned runs. Enter both optional counts. Hit batters and reaching on errors are not included in this WHIP calculation.

Does the simulator predict my next inning?

No. It adds the outs and earned runs you choose to your starting record. It permits one additional inning of three outs; undo or reset to try a different scenario. It does not simulate hits, walks, pitch locations or official scorer decisions.