King Mattresses

King mattresses offer a generous amount of sleeping space and are ideal for individuals or couples who want extra room to stretch out. A standard king mattress measures 5ft wide and fits all UK king size beds. This size provides a comfortable balance between space and support, making it a popular choice for master bedrooms.

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Frequently asked questions

Everything you need to know before you order.

  • A UK king size mattress measures 150cm wide by 200cm long (5ft x 6ft6). Note that king size mattresses are 10cm longer than double mattresses (200cm vs 190cm), so you cannot use a double mattress in a king bed frame — always check the size before ordering.

  • For back pain, we recommend our king size orthopaedic or back support mattresses, which are engineered with a firm, zoned spring or foam core to maintain spinal alignment. A king size is also beneficial for back pain sufferers as the extra width reduces the chance of sleeping in a twisted position.

  • Yes — a king size mattress typically weighs between 30kg and 50kg depending on construction. We always recommend two people for rotating or moving a king size mattress. Memory foam king mattresses in particular can be very heavy due to the density of the foam layers.

  • A king mattress (150 x 200cm) requires a king bed frame — it will not fit in a double frame. All our king bed frames are designed for this mattress size. Whether the frame uses a sprung slat, rigid slat, or solid panel base will not affect compatibility, though each base type may slightly influence the feel.

  • No — a king mattress (150cm wide) is 15cm wider and 10cm longer than a double. You would need a new king size bed frame. However, the investment is worthwhile — upgrading to a king size bed and mattress is one of the most impactful changes you can make to your sleep quality.