You spend about a third of your life on your mattress, and it is hard to judge in a few minutes in a showroom or from a photo online. These are the factors that matter most before you order.
Memory foam contours to the body and isolates motion, which suits couples, but it can sleep warm. Hybrids combine springs with foam or latex layers and are a popular all-round choice with good support and airflow. Latex is durable, responsive and naturally cooler, usually at a higher price. Traditional innerspring mattresses are bouncy and affordable but often less durable and less pressure-relieving.
Side sleepers usually do best on medium to medium-soft surfaces that let the shoulders and hips sink in. Back sleepers tend to prefer medium to medium-firm for support under the lower back. Stomach sleepers generally need firmer support to keep the hips from sagging. Heavier sleepers often prefer firmer and thicker mattresses, lighter sleepers softer ones. Firmness ratings differ between brands, so read reviews from people with a similar body type.
Good support keeps your spine in a neutral line. Reinforced edges make the whole surface usable and help when sitting on the side of the bed. If you share the bed, look for good motion isolation so you are not woken by a partner moving.
If you sleep hot, consider hybrids, latex or models with cooling covers and open-cell foams. Gel and copper infusions have mixed evidence, so treat them as a minor bonus rather than a reason to pay more.
Measure the room and the bed frame. Check the exact dimensions, because standard sizes differ between countries. Make sure the mattress height works with your frame and bedding, and that you can get it up the stairs: many mattresses ship compressed in a box.
Because comfort is personal, a sleep trial of 30 to 100 nights is valuable. Check how returns work, who pays for pickup, and whether a restocking fee applies. Read the warranty terms: sagging depth limits and what counts as a defect vary widely. Compare the final price including delivery rather than the headline discount, since mattress sales are frequent.