A single mattress is the most common size for children, teenagers and young adults. A single mattress measures 90 x 190 cm (3’ x 6’3"), which is suitable for most standard bed frames and bunk beds. A single mattress can fit in most small bedrooms and can provide adequate comfort and support for one person. British Bed Store sells a variety of single mattresses in different types and qualities, from anti-allergy to pillow top. You can also find matching headboards and bed bases to complement your single mattress.