A sofa that felt great after five minutes in a showroom can feel wrong after a week at home. The reason is usually the same: it was chosen on looks and first impressions, and the seating dimensions were never checked. Yet people spend hours a day on a sofa, reading, watching films and sometimes lying down. The parameters below help you judge comfort in both numbers and feel.
Seat depth
Depth is the distance from the front edge of the seat to the backrest. A shallow seat keeps you upright, which suits conversation and short sits but becomes tiring when you want to relax. A very deep seat means you either have to pull your legs up or put extra cushions behind you to lean back; otherwise the backs of your knees press against the front edge.
Checking the right depth is simple: sit all the way back. There should be a gap of a few fingers between the backs of your knees and the front edge, and your feet should rest comfortably on the floor. If family members differ a lot in height, a practical compromise is a deeper seat with extra back cushions for the shorter ones.
Seat height
The height of the seat above the floor decides how easy it is to sit down and get up. Low sofas look modern and relaxed, but for older people or anyone with knee problems standing up becomes harder. On a high seat, a shorter person's feet may not reach the floor properly.
A general rule: when seated, your thighs should be roughly parallel to the floor, with your knees at hip level or slightly below. When testing, also notice how far the soft seat sinks under you, because the measured height and the actual sitting height are not the same.
Firmness: soft is not always comfortable
A very soft seat feels pleasant at first, but as the body sinks in the lower back loses support and getting up gets harder. A very firm seat puts pressure on the hips and thighs during long sitting. Medium firmness is the most versatile choice for most households.
Firmness depends on the type and density of the filling. Dense foam holds its shape, while a softer top layer makes the first contact pleasant. Elastic webbing or a spring unit under the seat also changes the feel. When testing, do not just sit down once: see how the sofa behaves at the edge, in the middle and with two people on it.
Firmness also changes over time. Every filling softens a little in the first months, and low-density materials develop dips where people sit most often. If everyone in the family has a favourite spot, that difference becomes obvious after a few years. Removable seat cushions that can be turned over help spread the load. Asking the seller about the type and density of the filling, and looking at a cushion cross-section or a sample where possible, is more reliable than trusting a label like "medium firm". On a sofa that will also be used for lying down, a slightly firmer seat stays flat for longer.
Backrest and arms
Backrest height decides whether your head is supported. A low back looks light, but you cannot rest your head on it; if the sofa is mainly for watching films, a high back or adjustable headrests are more comfortable. The angle matters too: a very upright back makes sitting formal, while a strongly reclined one makes reading awkward.
Arms should be at a height where your arm rests naturally. If you often lie down on the sofa, the arm should be high and soft enough to support your head. Wide arms add to the overall width of the sofa, not to the seating area, so in a narrow room check that difference in the dimensions.
Practical rules for testing
- Everyone who will use the sofa most should take part in the test.
- Sit the way you do at home: lean back, lift your legs, lie down on your side.
- Stay in one position for at least a few minutes; discomfort often shows up later.
- Watch how quickly the seat cushions recover their shape after you stand up.
- Think about how the height works with your other furniture, especially the coffee table.
With made-to-order upholstered furniture, these parameters can be adapted to the household. Zaferoglu Mebel produces upholstered furniture to individual sizes, and seat depth, height and filling firmness can be agreed together at the start of an order.
