both top and bottom have at least 20 cm clearance, all the others are 15. shelves located above eye level are less useful as you cannot see the figures well. the view is mostly of their bases, so my top shelf is probably closer to 30cm maybe more, as the top has a bit of recessed headroom not visible from the front as the receptacle for the lights are hidden by a plate of wood that is much deeper than the ceiling. i didn’t install the very top most shelf nor the bottom most.