How big is a standard sofa?

How big a standard sofa is depends on how many people it is meant to seat. A standard two-seater sofa is usually around 48 to 72 inches in length by 30 to 40 inches in depth. Three-seater sofas typically measure at least 90 inches in length by 30 to 40 inches in depth. Explore a large collection of sofas on 1stDibs.