Seat Height Calculator
Find your ideal chair seat height from your body height — a min, ideal, and max range you can dial in on any adjustable office chair.
Your ideal seat height
Seat height is set to roughly match your popliteal (lower-leg) height, plus a small shoe allowance, so your feet rest flat on the floor with your thighs level. Adjust within the min–max range to suit your desk height and personal preference.
Why seat height drives the rest of your setup
Seat height is the foundation of a healthy seated posture. Set it to your popliteal height — the distance from the floor to the crease behind your knee — and your feet plant flat, your thighs run roughly horizontal, and there's no pressure cutting into the back of your legs. Get it wrong in either direction and the strain shows up elsewhere: too low and your knees ride higher than your hips; too high and your feet lose contact with the floor.
Once your seat height is set, it also determines how high your desk and monitor need to sit, so it's worth dialing in first, before you adjust anything else at your desk.
Frequently Asked Questions
How is ideal seat height calculated?
Seat height is set to roughly match your popliteal height — the distance from the floor to the back of your knee when seated — which runs about 0.25 times your total height, plus a small allowance of around 2.5 cm for shoes. For a 170 cm person that works out to about 45 cm.
Why does seat height matter so much?
When the seat pan matches your popliteal height, your feet rest flat on the floor and your thighs stay roughly horizontal, so there's no pressure cutting into the underside of your thighs and no strain from feet dangling or knees pushed up too high. Get this wrong and hip, knee, and lower-back discomfort tend to follow.
What's the min–max range for?
The calculator gives a small window (about ±2.5 cm) around the ideal height, not a single fixed number. Most gas-lift office chairs adjust across a range, so use it to find a comfortable setting that also works with your desk height and footrest, if you use one.
What if my feet don't reach the floor even at the lowest setting?
If your chair's lowest position is still above your ideal seat height, an adjustable footrest is the standard fix — it raises the effective floor so your feet stay supported without forcing the seat higher than your legs need.
Does this account for shoes?
Yes — the formula already includes a small allowance for typical shoe height. If you regularly sit barefoot or in very thick-soled footwear, treat the ideal figure as a starting point and fine-tune by a centimetre or two either way.
Educational estimate — not medical, physiotherapy, or occupational-health advice; consult a clinician or ergonomist for pain or medical needs.