King Size Mattresses

King, California King and Split California King mattresses from Tempur-Pedic, Sealy and Stearns & Foster, in foam, hybrid and innerspring builds from soft to extra firm.

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A standard king is 76 by 80 inches, sixteen inches wider than a queen. That extra width is the whole point: two adults each get roughly the space of a twin XL, so nobody negotiates for territory at 2 a.m. Every king here ships direct from Tempur-Pedic, Sealy, or Stearns & Foster, in foam, hybrid, and innerspring builds from soft to extra firm.

Three things to check before you buy. Measure the room: a king fits best with about 30 inches of walking space on three sides. Check the base: kings sit on one king foundation or two twin XL bases, and the two-base route lets you pair each side with its own adjustable base. And if you share the bed, foam and hybrid builds pass the least motion between sides.

100-night trial on qualifying mattresses. Not set on a size? Browse all mattresses.

King vs California King vs Split California King

SizeDimensionsBest for
King76 x 80 inchesCouples who want the most width
California King72 x 84 inchesTaller sleepers who want extra length
Split California KingTwo 36 x 84 inch mattressesCouples with an adjustable base who want to raise each side separately

Why shop at Sleepology

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King mattress FAQ

Is a California King bigger than a King?

Not overall. A California King is 4 inches longer but 4 inches narrower than a standard King, so it suits taller sleepers. A King gives you more width.

What size room do I need for a king mattress?

A king fits best with about 30 inches of walking space on three sides of the bed.

Can I use an adjustable base with a king?

Yes. Use one king adjustable base, or a Split California King with two bases so each side moves on its own. Shop adjustable bases.