Glossary
Seat depth
The front-to-back measurement of a chair seat, which needs to be long enough to support the full length of a tall person's thighs without cutting into the knees.
Seat depth is the distance from the front edge of a chair seat to the backrest, measured front to back rather than side to side. For a tall person with proportionally longer thighs, a seat that is too shallow leaves the legs unsupported past the knee, while a seat that is too deep pushes the knees up and forces the back away from the backrest.
The ideal seat depth leaves a gap of roughly two to three inches between the back of the knee and the front edge of the seat when sitting all the way back with the spine against the backrest. Many office chairs are built around average proportions and do not offer enough depth for taller users out of the box.
Chairs with a seat slider, which lets the seat pan move forward or backward independently of the backrest, solve this without needing a taller chair overall. When shopping, look specifically for a listed seat depth range or slider feature rather than just an overall chair height, since a chair can be tall enough for the backrest and still have a seat pan that is too short for long thighs.
Where this comes up
- Best Office Chairs for Tall PeopleBuying guide
- Best High Back Office ChairsBuying guide