With this tool you'll be able to calibrate your battery using the actuallymentor/battery tool that you can easily download at https://github.com/actuallymentor/battery

First of all, this tool will discharge your battery until it reaches 15%. When the 15% is reached, it will fully recharge the battery and keep it at 100% for 1 hour.Finally the battery will be discharged until it reaches 80% and will be kept on this percentage.

Download the script, move it in your favourite folder giving it the needed permissions.

chmod a+x /folder/to/calibration.sh

and execute it like a normal script

./calibration.sh

If you use your Mac always plugged in a wall socket and you have the maintainment set to 80%, I advise you to use this tool every three months.