When measuring a room, take into account any recesses, alcoves, bay windows and doors as shown in the diagram. To be sure measure the room to each corner, as shown below. Be careful not many rooms are square.
Make sure that you measure into the doorway. (A classic mistake is to miss this out; your measure could be up 15cm short if not done). Once you have these measurements you need to add 10cm on the length and width to allow for cutting in during your installation.
Remember when buying carpets generally they are manufactured at 4m and 5m widths (Other widths are available in more specialised carpets). If the room is more than 4m wide you may need to consider buying a 5m wide carpet or having a join in the carpet to accommodate the width.
If you are unsure, at Discount Capet Warehouse Ltd we offer a free measuring service.