King Size Mattresses (5ft)

Is a King Size Mattress Right for Your Bedroom?

A king size mattress is 15cm (6") wider and 10cm (3") longer than a double mattress. This additional space is a game-changer for several reasons:

• Extra Support for Couples: A king size provides enough width for two adults to sleep comfortably without disturbing one another.

• Better for Taller Sleepers: If you are over 6ft tall, the 200cm length of a king size mattress ensures your feet stay tucked in, avoiding the feeling of hanging off the end of a standard 190cm double.

• The Family Choice: Perfect for those weekend mornings when kids or pets join you in bed. If you need even more room, browse our range of Super King Mattresses.

Expert Guide to King Size Mattress Types

As industry leaders since 2003, we understand that "one size does not fit all." Our Sleep Experts and brand ambassadors suggest choosing your material based on your specific needs:

• Pocket Sprung Mattresses: The gold standard for motion isolation. Individual springs react only to the pressure applied directly to them, meaning you won’t feel your partner turning over.

• Hybrid Mattresses: Combines the traditional support of springs with modern layers of memory foam, gel, or latex. Ideal for those who want both bounce and body-contouring comfort.

• Orthopaedic Mattresses: Designed for those who prefer extra support. These are typically firmer and designed to distribute weight evenly to offer a firmer, more supportive feel.

 Finding Your Perfect Firmness:

Your sleeping position is the best indicator of the firmness level you need. For a detailed breakdown, read our Mattress Firmness Guide.

• Side Sleepers: Usually benefit from a Soft to Medium feel that cushions the shoulders and hips.

• Back/Front Sleepers: Generally require a Medium-Firm to Firm mattress to support a more neutral sleeping position and prevent the lower back from dipping.

Why Buy From MattressNextDay?

We aren't just a shop, we are the UK's sleep specialists with well over 32,000+ Trustpilot Reviews.

• Award-Winning Service: We are the 3-time NBF Online Retailer of the Year, ensuring high standards in product delivery, safety and sustainability.

• Expert Advice: We feature advice and guidance from leading brand ambassadors to help you choose the right product for your needs.

• Eco-Friendly Commitment: Add our Old Mattress Removal service at checkout, and we will recycle your old bed responsibly.

• Britain's Largest Mattress Retailer: Why shop around? With a massive amount of mattresses to choose from, we boast the largest mattress range in the UK, giving you a wide range of options to choose from.

What size is a king size mattress in cm?

A standard UK king size mattress is 150 x 200cm. If you are looking for a slightly different fit, we also stock European King Size Mattresses (160 x 200cm). View our Ultimate UK Bed and Mattress Size Guide for full details.

When might a king size mattress not be the right choice?

A king size mattress may not be the best choice if your bedroom space is limited. Because a king size bed measures 150 × 200 cm, you should ideally have at least 60–70 cm of space around the bed to move comfortably around the room. If your room is smaller, a double mattress may provide a better balance between sleeping space and usable floor area.

Will a king size mattress fit on my current bed?

Only if your current frame is a 5ft King size. If you are upgrading from a double, you will need a new King Size Bed Frame or King Size Divan Base.

• Expert Tip: To maintain your warranty, check that your bed slats are no more than 75mm (3") apart. Excessive gaps can cause a king size mattress to sag and damage the internal spring unit.

Can I get a king size mattress delivered tomorrow?

Yes! We offer Free Next Day Delivery on all sizes of mattress, including king sized mattresses, all across the UK mainland. We also offer Room of Choice delivery, ensuring your new mattress is exactly where you want it without any heavy lifting on your part.