How firm should a hybrid mattress be for side sleepers vs. back sleepers?

Side sleepers generally do best on softer hybrids (around 5–6/10) so the shoulder and hip can sink in enough to keep the spine neutral. Back and stomach sleepers usually want medium-firm to firm (6.5–8/10) to prevent the hips from dropping. Heavier sleepers (230+ lbs) are typically pushed one notch firmer than these defaults across the testing sources we read.