I’m using the bed with a 160x200 foam mattress from IKEA. It works perfectly fine, the mattress is coming of around 5cm on each side but that’s not noticeable when laying in bed at all.

the mattress doesn't really matter, or rather the bed can take a bit more weight; with a full extension I think a mattress up to 200 cm is also possible...the frame has a bit of sharp edges anyway and I think it will cut a good figure with an overlap of 5 cm each...