A room can have good materials, good light and well-chosen objects and still feel slightly wrong. Usually the cause is not the decoration. The sofa is too short for its wall, the coffee table is too small to reach, or the rug only covers the floor in front of the seats. These are proportion problems, and no number of cushions will fix them.
The good news is that proportion can be checked with a tape measure before anything is ordered. Below are the rules of thumb that work in most living rooms, with real numbers, in the order in which to apply them.
1. Sofa to wall: the two-thirds rule
A sofa placed against a wall looks settled when it takes up roughly two-thirds of the wall's length. On a 420 cm wall, that means a sofa of around 280 cm. Much shorter and it looks lost; much longer and it crowds doors, windows and side tables.
- Leave room at each end: 40–60 cm for a side table or a floor lamp, plus clearance for any door swing.
- Check the depth: overall sofa depth is typically 90–105 cm. In a narrow room, every extra 10 cm of depth comes out of the walkway.
- Look at the ceiling: under a ceiling above 3 m, a low sofa can look sunken; a higher back or taller armchairs help. Under a low ceiling, low backs keep the room open.
If the sofa floats in an open-plan space, measure it against the seating zone you want to create rather than the nearest wall. When a standard length misses the mark by a wide margin, many models in our sofa collection, such as the Platon sofa, can be made in custom dimensions on request.
2. Coffee table to sofa
The coffee table is the piece most often chosen too small. A common rule is that it should measure between half and two-thirds of the sofa's length: for a 240 cm sofa, a table of 120–160 cm.
- Height: level with the seat cushion or 2–5 cm lower. With typical seat heights of 42–46 cm, that gives a table of roughly 38–45 cm.
- Distance: 40–50 cm between the front of the sofa and the table edge, close enough to reach a cup, far enough to pass your legs.
- Shape: in front of a corner sofa, a square or round table fills the field between the two sides better than a long rectangle, and a round top is easier to walk around.
Before choosing from our coffee table collection, write down two numbers: your sofa length and its seat height. Together they rule out most of the wrong sizes at once. If a model you like, such as the Moon coffee table, is close but not quite right, ask about custom dimensions on request.
3. Rug to seating group
A rug should hold the seating group together, not lie in front of it like a doormat. The minimum is that the front legs of every sofa and armchair rest on the rug.
- For a three-seat sofa with two armchairs, 200 × 300 cm is a common starting size; larger groups usually need 250 × 350 cm or more.
- Let the rug extend 15–20 cm beyond each end of the sofa, so the sofa does not look wider than its base.
- In a medium-sized room, keep 30–60 cm of bare floor between the rug and the walls, so the rug reads as a zone and not as wall-to-wall carpet.
4. Distances between pieces
Proportion is also about the empty space. A group can have well-sized pieces and still fail because they stand too far apart or too close together.
- Conversation distance: seats facing each other work well within roughly 250–300 cm. Beyond that, people start raising their voices.
- Main walkways: about 90 cm; secondary passages at least 60 cm.
- Armchairs: angle them slightly towards the sofa and place a side table between them, rather than pushing them against the sofa arm.
We cover routes through a room in more detail in how circulation patterns influence furniture placement.
5. Visual weight and large rooms
Two sofas of the same length can feel very different. A low, deep sofa with wide arms carries more visual weight than a slim one on raised legs. Balance one heavy piece with lighter ones: a full, upholstered sofa next to armchairs on open legs, or a heavy stone coffee table with a lighter sofa. Keep arm heights and the table height in a related range, so the eye moves across the group without jumps.
Large living areas raise a different question: not how big the room is, but how big each seating zone should be. This applies to a large villa such as our project in Lomé, Togo as much as to an open-plan flat. A group of about 350 × 400 cm sits comfortably in a 60 m² room; two groups with a clear path between them often work better than one oversized arrangement.
6. Only then: decoration
Once the main pieces are sized and placed, decoration has something to build on.
- Artwork above a sofa is typically about two-thirds of the sofa's width and hung 20–25 cm above the back.
- Cushions should not eat into usable seat depth; on a 55 cm seat, two layers of large cushions can leave too little room to sit back.
- Before ordering, mark the outlines of the sofa, table and rug on the floor with painter's tape and live with them for a few days.
Every Sitdesign sofa is handmade in our own factory in Büyükçekmece, Istanbul, on a kiln-dried beech frame with high-resilience foam and sprung seating, and custom dimensions are available on request. Send us your wall lengths and a rough floor plan through our contact page, and we will suggest suitable sizes, send leather samples and prepare a quote.
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