All MacBook, MacBook Pro, and MacBook Air portable devices use a battery with an internal processor designed to maximize battery performance. In order to accurately predict remaining battery charge, the battery and processor must go through a calibration routine. In this guide, we'll show you how that process works.

Apple's newer MacBooks and MacBook Pros don't need to go through the same calibration process as older versions. Let your MacBook fully discharge and turn it off. Then, plug in the power cord and charge the battery to 100 percent. During this time, macOS will automatically calibrate the battery.

To calibrate an older MacBook:

Charge your Mac fully. Don’t rely on the battery menu. Instead, plug in the power adapter and charge your Mac until the light ring by the charging port or the light on the power adapter turns green and the onscreen battery menu indicates that your Mac is fully charged.