Standard one seat size for sofa set one person 60 CM ,2PERSON 120CM , 3 180CM BY AMERICAN ANTHROPOMETRY
12-18 inches
Most two seat sectional sleepers come with full size mattresses. Three seat sectionals come standard with queen size mattresses.
A standard sofa is about 7.5 or 8 feet long.
If you are talking about the depth being 40"...you may want to try turning the sofa on its side as you walk it through the opening.. standard doors are 30" to 36" wide.
Couch? (a sofa or seat)
What is the standard size of a sofa?
They have good material and padding to cushion your seat. The style of the sofa will also make a difference. The height of the sofa, depth of the seat and the amount of padding have to be just right or people will have difficulty getting up after being seated. For a sleeper sofa, you will need to evaluate the seating, since it will be more firm than others. In addition, you will need to check the comfort of the mattress, since the frame of the bed may be felt through the mattress.
A sofa comes in many sizes. They can seat 1 person or 10 people. There is no actual scale to determine if a sofa is small or large, but it depends on the relativity of the sofa to the room.
a long, soft seat with a back and usually arms
Hang the picture so the center of the picture is at eye level to the average person standing in front of the sofa. But, be sure that if someone sitting on the sofa, leans back, that their head doesn't hit the picture.
A chair is typically designed for seating one person, often with a backrest and armrests, whereas a sofa is larger and usually designed for seating multiple people. Sofas often have a longer seat depth and can accommodate more people comfortably compared to a chair.
Maybe chair is to sit as sofa is to recline.