Getting the mattress size right matters more than people expect — order the wrong size and it either won't fit your bed frame properly or will leave awkward gaps at the edges. Here's the full UK size breakdown.

UK Mattress Sizes at a Glance

  • 2'6" (Small Single): 75 x 190cm — compact single rooms and children's beds
  • 3'0" (Single): 90 x 190cm — the standard single size for teens and adults
  • 4'0" (Small Double): 120 x 190cm — a good compromise for smaller rooms needing more than a single
  • 4'6" (Double): 135 x 190cm — the standard UK double
  • 5'0" (King): 150 x 200cm — noticeably more width and length than a double
  • 6'0" (Super King): 180 x 200cm — the largest standard UK size

Always Check Against Your Bed Frame

Mattress sizes are standardised, but it's worth confirming the exact base dimensions of your bed frame before ordering rather than assuming — particularly with older or imported frames, where sizing can vary slightly. A mattress that's even a couple of centimetres out can leave an uncomfortable gap or hang over the edge of the base.

Choosing a Construction to Match the Size

Larger mattresses (king and super king) benefit most from a construction with strong edge support, since there's more surface area to keep consistent. Our Sprung mattresses are built with this in mind. For smaller sizes like single and small double, a Full Foam or Pocket 1500 construction can offer excellent pressure relief without needing the same edge reinforcement.

Buying for a Shared Bed

If two people are sharing, a king or super king reduces the chance of disturbing each other overnight, and a Pocket 1500 construction's independently wrapped springs further reduce motion transfer between sides.

Ready to Choose?

Browse our full Mattresses range across all six standard UK sizes, or see our Beds & Mattresses collection if you need a frame and mattress together.