King Medium Extra Firm NM® Mattress Selector

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.
Medium-firmness mattresses — often called medium-firm — sit right between plush and firm, which is why they're the most popular and versatile feel we carry. You get enough cushioning to relieve pressure with enough support to keep your spine aligned, making medium a safe choice for back sleepers, combination sleepers who change positions through the night, and couples who need a compromise between two preferences. Shop medium models from Sealy, Serta, Beautyrest, Stearns & Foster, iComfort and Tempur-Pedic across memory foam, hybrid, euro-top, pillow-top and tight-top builds — with free delivery across Canada. • Feel: medium sits between plush and firm — balanced and the most versatile of our four comfort levels • Also called "medium-firm" — the middle of the firmness scale • Best for: back sleepers, combination sleepers, couples, and most body types • Consider plush if you sleep on your side; firm if you sleep on your stomach or want more support • Constructions: euro-top, tight-top, pillow-top, memory foam and hybrid • Brands: Sealy, Serta, Beautyrest, Stearns & Foster, iComfort, Tempur-Pedic, Springwall & NM • Prices: from $171 to premium
Extra firm mattresses are the firmest, most supportive feel we carry — a hard, no-sink surface that holds your body on top of the mattress rather than letting it settle in. They're built for stomach sleepers, heavier-weight sleepers and anyone who finds a standard firm mattress still too soft, delivering maximum support and spinal alignment. Most use a tight-top or high-density foam construction (including orthopedic Chirofoam), with budget-friendly options that keep extra-firm support affordable. Shop Beautyrest, Serta, Chirofoam, Springwall and our own NM line — from $152, with free delivery across Canada. • Feel: extra firm is the firmest of our four comfort levels — a hard, no-sink surface • Best for: stomach sleepers, heavier-weight sleepers, and anyone who wants maximum support • Choose this over firm if a standard firm mattress still feels too soft • Consider firm or medium if you sleep on your side or want any cushioning • Constructions: tight-top and high-density foam (including orthopedic Chirofoam) • Brands: Beautyrest, Serta, Chirofoam, Springwall & NM • Prices: from $152 — an affordable, value-focused selection
NM mattresses are National Mattress's own line — quality construction at honest, direct prices across firmness levels and builds. Compare every option below by feel, size, and price.
King Medium Extra Firm NM® Mattress Selector

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King Medium Extra Firm NM Clear all
  • NM® HD+™ Core 6" Extra-Firm High Density Foam Mattress
    BEST IN CLASS BEST SELLING TOP RATED
    National Mattress HD 6-inch extra-firm foam mattress, grey damask tight-top, charcoal sides, Canada-flag badge NM Logo
    EX-FIRM
    • High Density Foam Core
    • High Density Foam Comfort Layer
    • Cotton Support Quilt
    • 5 Year Warranty
    • Made In Canada
    King In stock for fast delivery $328
    Compare at $599
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  • NM Orthopedic PLUS 10" Extra-Firm Euro Top Mattress
    BEST IN CLASS TOP RATED TRENDING
    National Mattress 10-inch extra-firm euro-top mattress, white damask-print top, black zigzag border band NM Logo
    EX-FIRM
    • Double Tempered Bonnel Coil with Edge Guard
    • HD+™ High Density Foam
    • Center & Lumbar Support
    • Cotton Support Quilt
    • 10 Year Warranty
    • Made In Canada
    King In stock for fast delivery $388
    Compare at $799
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  • NM Hi-Loft 10" Medium Firm Euro Top Mattress
    BEST IN CLASS BEST SELLING TOP RATED
    National Mattress 10-inch medium-firm euro-top mattress, white quilted top, tall black patterned sides NM Hi-Loft Collection Logo
    MEDIUM
    • 800 Hi-Loft Pocket Coil
    • Cool Gel infused memory foam
    • Luxurious Knit Fabric
    • 10 Year Warranty
    • Made In Toronto, Canada
    King In stock for fast delivery $535
    Compare at $1,099
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  • NM® HD+™ Advanced 8" Extra-Firm High Density Foam Mattress
    BEST IN CLASS BEST SELLING TOP RATED
    National Mattress HD 8-inch extra-firm foam mattress, white diamond-quilted tight-top, black quilted sides NM Logo
    EX-FIRM
    • Extra-Firm High Density Foam Core
    • HD Foam Support Layer
    • Cotton Fabric Quilted Top
    • 25 Year Warranty
    • Made In Toronto, Canada
    King In stock for fast delivery $564
    Compare at $999
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  • NM Cozy 8" Medium Firm Memory Foam Mattress
    CLEARANCE FLASH SALE BEST IN CLASS
    National Mattress 8-inch medium-firm memory-foam mattress, smooth white tight-top, charcoal sides, NM badge NM Cozy Collection Logo
    MEDIUM
    • High Density Foam Core
    • Cool Gel Memory Foam
    • Hypoallergenic Bamboo Cover
    • 10 Year Warranty
    • Made In Toronto, Canada
    King In stock for fast delivery $579
    Compare at $1,199
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  • NM® Hi-Loft™ Elite 12" Medium Firm Euro Top Mattress
    BEST IN CLASS BEST SELLING TOP RATED
    National Mattress 12-inch medium-firm euro-top mattress, white quilted dome top, black diamond-quilted sides NM Hi-Loft Collection Logo
    MEDIUM
    • 1000 Hi-Loft Pocket Coil with Foam Encased Perimeter
    • Cool Gel infused memory foam
    • Bio-Foam natural foam content reduces your carbon footprint
    • 10 Year Warranty
    • Made In Toronto, Canada
    King In stock for fast delivery $698
    Compare at $1,299
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  • NM® Hi-Loft™ Elite 12" Extra-Firm Tight Top Mattress
    BEST IN CLASS BEST SELLING TOP RATED
    National Mattress 12-inch extra-firm tight-top mattress, white diamond-quilted top with black quilted sides NM Hi-Loft Collection Logo
    EX-FIRM
    • 1000 Hi-Loft Pocket Coil with Foam Encased Perimiter
    • HD High Density Support Foam
    • Bio-Foam natural foam content reduces your carbon footprint
    • 10 Year Warranty
    • Made In Toronto, Canada
    King In stock for fast delivery $698
    Compare at $1,299
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  • NM® HD+™ Core Advanced 10" Extra-Firm Flippable High Density Foam Mattress
    BEST IN CLASS BEST SELLING TOP RATED
    National Mattress HD 10-inch extra-firm flippable foam mattress, white quilted top with charcoal sides NM Logo
    EX-FIRM
    • HD+™ High Density Foam Core
    • Firm BioComfort™ Foam
    • Dual Sided Cotton Support Quilt
    • 25 Year Warranty
    • Made In Canada
    King In stock for fast delivery $759
    Compare at $1,599
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  • NM® HD+™ Core Advanced 13" Extra-Firm Pillow Top Foam Mattress
    BEST IN CLASS TOP RATED TRENDING
    National Mattress HD 13-inch extra-firm pillow-top foam mattress, tall black quilted sides, white diamond top NM Logo
    EX-FIRM
    • Extra-Firm High Density Foam Core
    • High-Density Foam Support Layers
    • Bamboo Quilted Top
    • 25 Year Warranty
    • Made In Toronto, Canada
    King In stock for fast delivery $906
    Compare at $1,599
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  • NM Cozy 12" Medium Firm Memory Foam Mattress
    BEST IN CLASS TOP RATED TRENDING
    National Mattress 12-inch medium-firm memory-foam mattress, tall white channel-quilted top, grey woven sides NM Cozy Collection Logo
    MEDIUM
    • Optimal High Resilient Bio-Foam Core
    • Gel Infused Visco Memory Foam
    • Cotton Channel Quilted Cover
    • 10 Year Warranty
    • Made In Toronto, Canada
    King In stock for fast delivery $967
    Compare at $1,799
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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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