A UK double bed is 135 cm wide and 190 cm long: 4ft6 by 6ft3, or 54 x 75 inches. That's the mattress size. A double bed frame is bigger; our upholstered double frames measure about 56 x 82 inches (142 x 208 cm) including the headboard.

UK beds come in five standard sizes: single 90 x 190 cm (3ft), small double 120 x 190 cm (4ft), double 135 x 190 cm (4ft6), king 150 x 200 cm (5ft) and super king 180 x 200 cm (6ft). Those are mattress measurements. The bed frame around the mattress is always a little larger, so measure the room against the frame, not the mattress.