A general rule is that the deeper the seat depth, the lower the seat height needs to be and vice versa. Seat heights on modern comfortable couches can vary, but a standard range is typically between 15 and 20 from the floor to the top of the cushion, with an average range falling between 17 to 18.

Determining a comfortable seat height is primarily a matter of ergonomics relative to an individual's popliteal height—the distance from the underside of the foot to the underside of the thigh at the knee. For most adults, a standard seat height of 17 to 19 inches (43 to 48 cm) from the floor to the top of the seat is considered the "gold standard." At this height, the average person can rest their feet flat on the floor, which is crucial for blood circulation and reducing pressure on the lower back. If the seat is too high, the legs dangle, putting stress on the back of the thighs; if it is too low, the knees are pushed above the hips, which can be uncomfortable for the joints over long periods. In an office setting, an adjustable chair is essential to fine-tune this measurement, ensuring the hips are slightly higher than the knees. For dining or casual seating, the height must also consider the "apron" of the table, ideally leaving 10 to 12 inches of space between the seat and the tabletop to allow for comfortable leg movement and ease of standing up or sitting down.