The joists and surfaces between floors in a home are 12-14 inches thick in total, bringing the distance between the floor and ceiling in each level closer to 7 feet.
I’ve phrased that badly. Obviously the stairs go floor to floor... wall height would obviously be floor to floor minus joists, flooring, ceiling material.
The joists go on top of the studs, not between them.
'standard' ceiling height is 2.4m.