About

Why ERA Calculator exists and how its calculations work.

ERA Calculator is a free, independent set of baseball calculation tools. It is built around one goal: making the most-searched pitching stat quick to calculate and impossible to get wrong because of innings notation.

How the numbers are calculated

Every tool converts innings pitched into outs before doing any math, so 6.1 is always 6⅓ innings and 6.2 is always 6⅔. Results are computed with whole-number arithmetic and rounded to two decimal places. The calculation code is covered by automated tests, including the .1 and .2 cases.

Calculations happen entirely in your browser. There are no accounts and nothing you type is sent anywhere — see the privacy page for details.

Tools

ERA Calculator — earned run average from earned runs and innings pitched.
ERA Predictor — your ERA after the next outing.
ERA Goal Calculator — what it takes to reach a target ERA.

ERA Calculator is not affiliated with Major League Baseball or any league, team or governing body.