If you can slide your hand into the hollow of your back so that it fits snugly and if you can turn over easily, the mattress is about the right firmness for you.
Kui sa saad oma käe selja nõgususe alla libistada, nii et see mahub sinna parajasti ära, ning end hõlpsasti ümber keerata, on madrats enam - vähem sobiva kõvadusega.