What seat depth should an office chair have?

Standard seat depth for commercial office chairs is 15"–18", adjustable from front to back on better models. The correct depth positions the front seat edge 2–3 finger widths from the back of the knees when seated fully back against the lumbar support. Too-deep seats cut into the back of the knees and restrict circulation; too-shallow seats don't support the thighs adequately. Seat depth adjustment (sliding the seat pan forward or backward) is a key feature that distinguishes ergonomic chairs from basic task chairs. FindOfficeFurniture.com has office chairs with seat depth adjustment — call 888-719-4960.