For most UK living rooms, A2 is the sweet spot for a single statement print above a sofa. It reads confidently without dominating the wall or dwarfing a standard 3-seater.
If your room is generous - high ceilings, wide sofa, or a feature wall with no other art - jump up to A1. It is roughly the size of two A2 prints side by side and holds a big empty wall the way nothing smaller can.
Prefer a cluster? Three A3 prints hung tightly (5 – 8 cm apart) read as one composition and give you more flexibility to change one out later.
Above a mantelpiece, match the print width to roughly two thirds of the mantle. A3 landscape suits most standard fireplaces; A2 works for wider surrounds.