Baseball ERA Calculator
Calculate a pitcher earned run average, the classic measure of how many earned runs a pitcher gives up per nine innings. The formula is earned runs multiplied by nine, divided by innings pitched. Because a standard game is nine innings, multiplying by nine scales the rate to a full game so you can compare a starter and a reliever fairly. Enter the earned runs a pitcher allowed and the innings pitched, and note that a partial inning is counted in thirds: one out is 0.1, two outs is 0.2, so two and a third innings is entered as 2.1. The tool converts that notation to true thirds before dividing, then rounds the ERA to two decimals. A lower ERA is better, and elite starters often sit under three. Everything runs locally in your browser.
How to use Baseball ERA Calculator
- Enter the earned runs allowed.
- Enter the innings pitched.
- Read the ERA, earned runs times 9 over innings.
- Compare the ERA against league averages.
Frequently asked questions
What is the ERA formula?
Earned run average is earned runs times 9 divided by innings pitched, which scales a pitcher runs allowed to a standard nine inning game.
Why multiply by 9?
Multiplying by 9 projects the earned runs over a full nine inning game, so pitchers with different workloads can be compared on equal footing.
How do partial innings count?
Innings pitched use thirds, so 6.1 means six and one third innings; enter partial innings as decimals like 6.33 for an accurate result.
What is Baseball ERA Calculator?
Calculate a pitcher earned run average, the classic measure of how many earned runs a pitcher gives up per nine innings. The formula is earned runs multiplied by nine, divided by innings pitched.
Is Baseball ERA Calculator free to use?
Yes. Baseball ERA Calculator is completely free, with no sign-up and no usage limits.
Does Baseball ERA Calculator work in a web browser?
Yes. Baseball ERA Calculator runs in any modern web browser. There is nothing to download or install.
Is my data private with Baseball ERA Calculator?
Yes. Baseball ERA Calculator runs entirely on your device in your browser, so nothing you enter is uploaded to a server.
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