It pays to take your time when selecting a mattress, since “you’ll spend a third of your life on it over the next 8 to 10 years,” says Perry Davis, a division president at Leggett & Platt, a company that makes bedding components in Carthage, Missouri. There are three main types to choose from:

Innerspring construction (steel coils topped with layers of padding) is the most common. One good measure of how well a mattress will support your body is the number of coils it contains. Davis recommends a minimum of 350 coils for a full-size mattress, 480 for a queen, and 580 for a king.

Air-filled models (composed of air chambers surrounded by foam) let you adjust the firmness; opt for a top layer of high-density foam.

Foam mattresses come in latex (made of natural or synthetic rubber), polyurethane (which varies in density), and viscoelastic (one example is memory foam, which molds to your body’s shape). Foam retains heat well, so if you get hot while sleeping, look for open-cell construction for maximum breathability.

Prices range considerably: For an innerspring model, expect to spend anywhere from several hundred dollars to $2,000; for memory foam, from $1,000 to up to $5,000 (for a thicker mattress, perhaps covered in silk or satin).

A mattress is an investment, so care for yours well. Every few months, flip and rotate it for even wear, and vacuum the surface. Once a year, air it out by opening a window for a few hours.

Shown from top to bottom:

Royal Pedic Organic cotton three-inch pillow-top pad, ABC Carpet & Home, $1,588 for queen
To Buy: 212-473-3000.

SpringFree by Sealy Posturepedic mattress, $1,899 to $3,199 for queen (includes box spring). Synthetic latex foam. Antimicrobial and dust mite–resistant.
To Buy: www.sealy.com for retailers.

Royal Pedic Organic mattress, ABC Carpet & Home, $2,199 for queen. Organic cotton and wool.
To Buy: 212-473-3000.

Queen Plush Innerspring mattress by Room & Board, $499. The cover repels both moisture and stains, and it’s bacteria-, mold-, and dust mite–resistant.
To Buy: 800-301-9720.