In the UK, bed sizes are measured according to the size of the mattress they hold, which is a standard measurement. However, the actual dimensions of the bed frames can vary according to their shape and style, which is what can often cause confusion. 

 A common mistake is to use the mattress size measurements for the required space, but you should always look at individual bed frame dimensions for exact measurements, as they will vary from frame to frame, and almost always be slightly larger than the mattress dimensions. 

 UK Manufacturers, produce their mattresses in Metric units (centimetres and metres) as a standard.