King Compatible with Adjustable Bed Adjustable Bed Base Friendly Mattresses for Standard Bed Frames Default Category

King mattresses measure 76" × 80" — the widest standard size, giving each partner the same personal space as a twin. They're the top choice for couples who want maximum room, families who co-sleep, and larger master bedrooms. Compare every king option below by brand, feel, and price.
Shop adjustable base friendly mattresses from Beautyrest, Serta, Sealy, Tempur-Pedic, Springwall, iComfort, and Stearns & Foster at National Mattress — 169+ models in memory foam, hybrid, latex, eurotop, and tight-top constructions from $59 to $6,640. Every mattress in this collection is manufacturer-verified to flex and articulate with an adjustable base without voiding the warranty. Available in Twin through King sizes with firmness levels from extra firm to plush, all built with CertiPUR-US® certified foams, including Canadian-made options. Free delivery is available, along with a 365-night sleep trial and 5–15 year warranty coverage.
These mattresses are built for a standard bed frame, box spring or platform bed rather than an adjustable base — solid, no-flex support for a classic setup. Shopping by feel or build instead? Browse by comfort (plush, medium, firm) or by type (memory foam, hybrid, pocket coil, traditional). Using an adjustable base? See our adjustable-bed-compatible mattresses. Every order includes a 365-night sleep trial and free delivery across Canada.

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Upgrade your sleep at National Mattress

Discover a mattress that transforms your sleep into a truly rejuvenating experience. We offer a wide variety of options to suit every sleep style and preference, ensuring a better night's sleep.

Why Choose Us?

Variety: From plush to firm, we have options for every body type and sleep style.
Quality: Trusted brands and top-notch materials for long-lasting comfort.
Sleep Trials & Warranties: Enjoy peace of mind with flexible trials and warranties.
Expert Advice: Get personalized recommendations from our sleep specialists.

Mattress Selection Includes

Memory Foam: Contours to your body for personalized comfort and pressure relief.
Hybrid: Combines responsive springs with foam for balanced support and comfort.
Innerspring: Provides firm support, bounce, and cooling airflow.
Latex: Hypoallergenic, eco-friendly, and exceptionally comfortable.
Adjustable Beds: Customize your sleep position for optimal comfort.

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