Sofa Size Calculator
What size sofa fits your room?

Measure the wall the sofa will sit against and take 15 to 20cm off each end. For a 3.6m wall that gives a maximum of about 320cm, so a three-seater at 200 to 230cm sits comfortably with room to breathe.

Leave 75cm for any walkway behind or beside it, 90cm where it is the main route through the room, and 40 to 45cm between the sofa and the coffee table.

Three measurements: the wall it sits against, the room depth in front of it, and every doorway, turn and stairwell between the front door and the room. The third is the one people skip.

Around 90cm is upright and formal, 100cm suits most rooms, and beyond 110cm you are buying a lounging sofa. Deep seats need deep rooms — every extra centimetre of depth is one less in your walkway.

55 to 60cm each is comfortable. Divide the sofa length minus the arms by that figure and you have the honest seat count, which is often one less than the label claims.

Look for a knock-down frame, where the back and arms unbolt, or a modular design delivered in sections. Removable legs alone can buy you 15cm. Ask for the packed dimensions before ordering, not after.

Roughly 1.5 to 2.5 times the screen diagonal. A 55 inch television wants 2 to 3.5 metres. Closer than that and you see the pixels; further and you lose the detail.

Look at the rub count: 20,000 Martindale is fine for a spare room, 30,000 or more for a family sitting room. Tight weaves in wool or performance linen wear best; loose bouclé and pure linen look wonderful and pill quickly under daily use.

Typically 180 to 220cm overall. Anything under 190cm seats three only if they are friendly — the arms take 25 to 30cm before anyone sits down.

A sofa goes through a doorway on its side, so what has to clear is the depth, not the length. Allow 4cm of hand room. A standard 76cm internal door takes most sofas up to about 100cm deep.

A two-seater at 150 to 170cm, or a compact three-seater at 180cm with slim arms. Choose raised legs and a low back — seeing floor beneath the sofa makes a small room read larger.

Rarely. A corner sofa fixes the layout permanently and eats two walls. In a small room, a sofa plus one armchair gives the same seating with far more flexibility.

Not necessarily. Floating a sofa 10 to 15cm off the wall makes a room feel more considered, and in a large or open-plan space a sofa with its back to the room defines the seating zone.

The rug should be at least as wide as the sofa, and ideally wider than the whole seating group. Our rug size calculator works this out alongside your furniture.

A frame that lasts starts around £1,200 and rises steeply with hand-tied springs, feather fill and heavier fabrics. Below about £700 you are buying a stapled softwood frame and foam that will flatten within a few years — fine for a rental, false economy for a home.