The wall behind a sofa is the most attempted gallery wall in the home and the most often botched. The size question has a clean answer — two thirds of the sofa — but a gallery wall is not one piece scaled up. It is a composition, and compositions fail for reasons that have nothing to do with size.
Odd numbers, or a deliberate grid
There are two arrangements that reliably work above a sofa, and a lot of ground between them that does not.
The first is a grid: identical formats in identical frames, two or three across, one or two down, equal gaps throughout. It is formal, it is quiet, and it is very hard to get wrong. Four 50×70 in a two-by-two block spans 104 cm and suits a 160 cm sofa.
The second is an odd-numbered row: three or five pieces, mixed formats, aligned on their centres. Three works above almost any sofa; five needs 240 cm or more of sofa to sit under.
What fails is the in-between — four pieces of mixed sizes in a loose scatter. Even numbers want symmetry, mixed sizes want asymmetry, and the two pull against each other.
Start from the middle and work out
Hang the centre piece first, positioned by the rules that govern any single work above furniture: centred on the sofa horizontally, and with its own centre around 145 cm from the floor. That is covered in how high to hang art.
Then add outward in pairs, one to each side, keeping gaps equal. Building left to right is how arrangements end up off-centre — by the time you reach the far end, the accumulated error is visible against the sofa below.
HILMA AF KLINT - THE TEN LARGEST, ADULTHOOD, NO. 7 PLAKAT
Bauhaus orange on blue poster
A Retrospective - Mark Rothko Poster
Pumpkin Forever - Yayoi Kusama Poster
Yayoi Kusama - Red Dots Poster
Bauhaus Woman 02 - David Wolf
Align centres, not tops
The rule that separates a considered wall from a busy one: when frames are different heights, line up their horizontal centres, not their top or bottom edges. Aligning tops leaves the bottom edges ragged, and the eye reads the raggedness before it reads the art.
Twelve arrangements, each with total dimensions and the furniture width it suits, are set out in the gallery wall guide.
The arrangement must not outgrow the sofa
A gallery wall that extends past the arms of the sofa on either side stops belonging to it and starts competing with it. Keep the full span — outermost frame edge to outermost frame edge — inside the width of the sofa, and ideally around two thirds of it.
For a 220 cm sofa that means a total span of roughly 147 cm: three 50×70 with 4 cm gaps comes to 158 cm, which is close enough; two 70×100 with a 4 cm gap comes to 144 cm, which is exact. The poster size guide lists every format.
One frame finish, or one obvious rule
Mixing frame finishes across a gallery wall works only when the mix follows a rule the eye can find — all oak on the outside and black in the middle, say. A random mix reads as pieces collected over time, which is charming in a hallway and untidy above a sofa. Oak and black run through all five sizes; see the the frames.
For choosing the work itself rather than the arrangement, the living room collection is where to start.