It’s normal, but try to calibrate your battery once. (discharge fully, leave overnight, recharge fully, keep plugged for 3 hrs after LED turns blue).
The battery percentage display has some tolerance, but since a lot of users asked for it, we’ve added it along with the 3-bar display. The max charge capacity depends on the battery’s age & condition (which again has a little tolerance out of the factory), the temperature and your usage pattern (using Presentation mode too often draws much more power and can prematurely age your battery).