Home Mattresses Small Double Mattresses 4'0 Small Double Mattresses 4'0 Measuring 120cm by 190cm, a small double mattress is 15cm narrower in width than standard double mattresses, fitting 4 foot beds – the smallest double bed size. Shop our collection of small double mattresses for your 4 foot double bed. From a 2000 pocket sprung mattress or 3000 pocket sprung mattress, rolled mattress, memory foam mattress, Orthopaedic beds and more. Designed for special size beds. There are no products matching the selection. What does a UK small double mattress measure? A UK small double mattress measures 120cm in width and 190cm in length, making it slightly smaller than the standard UK double mattress. We deliver all our UK small double mattresses worldwide. What style of UK small double mattresses do you sell? We sell a variety of styles of UK small single beds, with our range offering you options such as contract hotel & leisure, non-sprung and pocket sprung mattresses.