Our Factory Clearance Sale is on now!

King Medium Compatible with Adjustable Bed Adjustable Bed Base Friendly Temperature-Regulating Mattresses All

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
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.
A temperature-regulating mattress works to keep you at a comfortable, balanced temperature all night and all year — not just cooling you down, but adapting as your body and the seasons change so you don't wake up too hot or too cold. These mattresses use heat-responsive and breathable materials — phase-change covers, gel and graphite foams, Tencel and natural fibres, and airflow-promoting coils — to absorb and release warmth as needed. It's ideal if you run hot and cold, share a bed with a partner who sleeps at a different temperature, or just want consistent comfort through every season. You'll find temperature-regulating builds across every brand — Sealy, Serta, Beautyrest, iComfort, Tempur-Pedic, Chirofoam and our own NM line. Sleep hot specifically? See our cooling mattresses. Every mattress includes a 365-night sleep trial and free delivery across Canada. • What it does: holds a balanced, neutral temperature — adapts so you're not too hot or too cold • How it works: phase-change covers, gel & graphite foams, Tencel/natural fibres and breathable coil airflow • Best for: people who run hot and cold, couples with different sleep temperatures, and year-round comfort • Cooling vs regulating: cooling sleeps cold (for hot sleepers); regulating holds a steady, balanced temp • Across every brand and firmness • Every order: 365-night sleep trial, price-match guarantee & free Canada-wide delivery
King Medium Compatible with Adjustable Bed Adjustable Bed Base Friendly Temperature-Regulating Mattresses All
Loading recommendations...
  • Stearns & Foster Lux Estate 16-inch medium-firm euro-top mattress, teal damask top, navy sides, coral tabs Stearns & Foster Lux Estate Luxury Mattress Logo
    • Indulge Quilt With Silk & Wool Fibres
    • Cooling Fibres With Tencel™
    • PrecisionMatch™ Memory Foam
    • Supportive Latex Comfort Layer
    • PrimaSense™ Gel Infused Comfort Layers
    • Intellicoil® Innerspring (Pocket Coil) With Intellicoil® Micro HD
    • Handmade By Certified Master Craftsman
    King $3,349
    Compare at $5,499
    In-Store availability icon On Display:
    Estimated delivery icon Order today to receive by Tue, Nov 10
  • Evergreen 100% organic 10-inch medium-firm latex mattress, white diamond-quilted top, brown base trim Evergreen Sleep Pure 100% Organic Latex Mattress Collection Logo
    • 100% Certified Natural Organic Latex
    • Global Organic Latex Standard – Certified 100% Natural
    • Eco-Institute – No Fillers or Hazardous Particles
    • Oeko-Tex Standard 100 – No Harmful Substances
    • ABC Research Laboratories – Certified Antimicrobial
    King In stock for fast delivery $2,650
    Compare at $4,899
    Online availability icon In-Stock Only 1 left!
    In-Store availability icon On Display:
    Free delivery availability icon Free delivery to M5H 2N1 as soon as Tomorrow, Oct 26
    Pickup available icon Only Pickup available to
    M5H 2N1
  • Sealy Essentials 10.5-inch medium-firm euro-top foam mattress, blue-speckled top, white sides on black base Sealy Essentials Mattress Logo
    • CleanProtect™ Fabric
    • SealyLoft™ Quilt with Moisture Wicking Fibres
    • CertiPUR-US™ SealySupport™ HD Foam
    • CertiPUR-US™ SealySupport™ HD Core
    • SealySupport™ HD Foam
    King $655
    Compare at $1,499
    In-Store availability icon On Display:
    Estimated delivery icon Order today to receive by Tue, Nov 10
  • Sealy Essentials 11-inch medium-firm tight-top mattress, blue-speckled flat top, white pinstriped sides Sealy Essentials Mattress Logo
    • CleanProtect™ Fabric
    • SealyLoft™ Quilt with Moisture Wicking Fibres
    • CertiPUR-US™ SealySupport™ HD Foam
    • Posture Touch® Pocket Coils
    • EssentialEdge™ Coil Support
    King $675
    Compare at $1,599
    In-Store availability icon On Display:
    Estimated delivery icon Order today to receive by Tue, Nov 10
  • Beautyrest 14-inch medium-firm pillow-top mattress, grey textured cover with charcoal sides, teal piping and side handles Beautyrest Mattress Collection Logo
    • 875 Beautyrest® Pocketed Coil Technology
    • Beautyrest® ActiveResponse Memory Foam
    • Beautyrest® Plush Gel Foam
    • Beautyrest® Support Foam
    • Beautyrest® Antimicrobial Fibre Technology
    King In stock for fast delivery $1,034
    Compare at $2,399
    Online availability icon In-Stock Only 1 left!
    In-Store availability icon On Display:
    Free delivery availability icon Free delivery to M5H 2N1 as soon as Tomorrow, Oct 26
    Pickup available icon Only Pickup available to
    M5H 2N1
  • Serta Perfect Comfort X 14-inch medium firm euro-top mattress, charcoal cover, grey feather quilt top Serta Perfect Comfort X Luxury Mattress Logo
    • 1250 Series 5 ZoneActive™ Pocket Coil System
    • Perfect Conform™ Graphite Memory Foam
    • CoolFeel Fabric™
    • QuiltLoft™ Memory Foam
    • PerfectPure™ Fibre
    • Designed and Made in Canada
    King $1,614
    Compare at $3,899
    In-Store availability icon On Display:
    Estimated delivery icon Order today to receive by Tue, Nov 10
  • Sealy Posturepedic Plus 1200 Series 15.5-inch medium-firm euro-pillow-top mattress, domed cream top, blue sides Sealy Posturepedic Plus Mattress Logo
    • CleanProtect™ Cover
    • Sealy AirSense™ Fibres Topped with SealyIce™ Yarn
    • CertiPUR-US™ SealyComfort™ Gel HD Foam
    • Posture Grid® Coil System featuring PostureSense™ Nano Coils
    • SolidEdge™ PRO
    • PROBACK® Plus Quilt with Targeted GelSense™ HD Memory Foam
    King $1,279
    Compare at $2,999
    In-Store availability icon On Display:
    Estimated delivery icon Order today to receive by Tue, Nov 10
  • Sealy Essentials 8-inch medium-firm tight-top foam mattress, quilted blue-grey top, white sides, navy piping Sealy Essentials Mattress Logo
    • CleanProtect™ Fabric
    • SealyLoft™ Quilt with Moisture Wicking Fibres
    • CertiPUR-US™ SealySupport™ HD Foam
    • CertiPUR-US™ SealySupport™ HD Core
    • SealySupport™ HD Foam
    King In stock for fast delivery $591
    Compare at $1,399
    Online availability icon In-Stock Only 1 left!
    In-Store availability icon On Display:
    Free delivery availability icon Free delivery to M5H 2N1 as soon as Tomorrow, Oct 25
    Pickup available icon Only Pickup available to
    M5H 2N1
  • BEAUTYREST® BeautySleep® 11" Medium Firm Euro Top Mattress - 1 Beautyrest BeautySleep Logo
    • 815 Original Beautyrest® Pocketed Coil®
    • Gel-Infused Fibre Blend
    • AirFeel® Foam
    • Gel Foam
    • High-Density Foam Encasement
    King In stock for fast delivery $810
    Compare at $1,899
    Online availability icon In-Stock Only 1 left!
    In-Store availability icon On Display:
    Free delivery availability icon Free delivery to M5H 2N1 as soon as Tomorrow, Oct 26
    Pickup available icon Only Pickup available to
    M5H 2N1
  • National Mattress 12-inch medium-firm memory-foam mattress, tall white channel-quilted top, grey woven sides NM Cozy Collection Logo
    • 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 $619
    Compare at $1,799
    Online availability icon In-Stock Only 2 left!
    In-Store availability icon On Display:
    Free delivery availability icon Free delivery to M5H 2N1 as soon as Tomorrow, Oct 26
    Pickup available icon Only Pickup available to
    M5H 2N1
  • Sealy Posturepedic Luxury 13.5-inch medium-firm hybrid mattress, grey wavy tight-top, black sides, blue badge Sealy Posturepedic Luxury Mattress Logo
    • SealyCool™ Fabric Premium Ultra-Stretch Cover
    • Silhouette™ Memory Foam
    • SealyMAX™ Core System featuring SealyResponse™ PRO & SolidSupport™ Pocket Coils
    • SolidEdge™ PRO Coil Edge
    • Sealy ComfortSense™ Memory Foam with SealyCool™
    • Zoned Pocket Coil Support
    King $1,812
    Compare at $4,299
    In-Store availability icon On Display:
    Estimated delivery icon Order today to receive by Tue, Nov 10
  • Beautyrest Centennial 15.5-inch pillow top medium-firm mattress, black sparkled pillow top with grey sides Beautyrest Centennial Luxury Mattress Logo
    • 1850 T3 Triple Stranded Pocketed Coil® and Micro Coil Technology
    • SurfaceTouch™ Gel Memory Foam
    • Self-Response™ Latex
    • Beautyrest® Gel Memory Foam
    • Beautyrest® Gel Support Foam
    • Sleep Climate™ Surface enhanced with cooling yarn
    King $2,959
    Compare at $4,199
    In-Store availability icon On Display:
    Estimated delivery icon Order today to receive by Tue, Nov 10

Items 13-24 of 55

Showing of products

Loading recommendations...