A typical three-cushion sofa is 84 inches wide -- the width is measured between the outer edges of the arms -- by 35 inches deep. A love seat with two cushions is usually 60 inches wide by 35 inches deep. The normal height for both pieces is 37 inches from the floor to the top of the back seat cushion. Because no set standards exist for furniture size, these dimensions may vary by as much as 2 inches within the typical range.
For both sofas and love seats, the typical 35-inch depth includes the seat and back support. The seat itself is usually 24 to 28 inches deep, with the back support and back cushion taking up 7 to 11 inches of the total depth measurement. The seat height is typically 16 inches from the top of the seat cushion to the floor.
Scaled-down sofas and love seats that fit into small spaces are often called apartment-sized furnishings. Apartment-sized sofas sofas are 81 inches wide or less; the love seats are 58 inches wide or less. The depth may be scaled down to as little as 30 inches, with a shallower back cushion to maintain the 24-inch seat depth.
With a large living room or an open floor plan with abundant space, oversized sofas and love seats provide the appropriate scale. An oversized sofa is at least 90 inches wide, and an oversized love seat is at least 71 inches wide. Depth may run up to 40 inches, and seat height may also be increased.
Many furniture companies offer custom options to tailor a sofa or love seat exactly to your space needs. For example, a standard-length sofa may need to be made narrower or with a reduced back height to get it through a narrow doorway. In small homes, you can save space and still get the full seating width by eliminating the arms of the sofa or love seat.