Will calibrating a mac battery increase capacity
I heard that i tried doing it to my mac before: 1202 mAh (bad) after: 2492 (poor)
you should calibrate if the capacity goes down a bit
MacBook Pro 13″, macOS 10.13
http://www.apple.com/batteries explains more how their batteries operate.
While calibration can help, what really makes batteries function or not is their age, and number of cycles used.