The ideal chair height allows your feet to rest flat on the floor (or a footrest) with your knees bent at approximately 90-100°. Your thighs should be parallel to the ground, and your hips should be slightly higher than your knees. For most people, this falls between 40-55 cm (16-22 inches) from the floor. Use our calculator above — enter your height and desk height for a personalized recommendation.

Armrests should be set so your forearms rest comfortably with your elbows bent at roughly 90-100°. Your shoulders should remain relaxed and not elevated. If armrests are too high, they force your shoulders up (leading to neck and shoulder pain). If too low, you'll slouch to reach them. The ideal armrest height from the floor is typically your seat height plus 17-23 cm (7-9 inches), varying with torso length.

Your screen should be approximately an arm's length away — typically 50-70 cm (20-28 inches) from your eyes. You should be able to read text comfortably without leaning forward. The top of the screen should be at or slightly below eye level, and the screen should be tilted back 10-20° to reduce glare. For larger monitors (27" and above), you may need a slightly greater distance. If you wear bifocals, position the screen lower to avoid tilting your head back.

You need a footrest if: (a) your desk is too high relative to your height, forcing you to raise your chair so your feet no longer rest flat on the floor; or (b) you are shorter than about 160 cm (5'3") using a standard 72-75 cm desk. A footrest helps maintain proper knee and hip angles, reduces pressure on the back of the thighs, and improves circulation. Choose an adjustable footrest with a non-slip surface.

Both knees and elbows should be at approximately 90-100° for optimal ergonomic positioning. A slightly open angle (95-110°) can also be comfortable and promotes better circulation. Avoid acute angles (less than 90°) which compress joints and restrict blood flow. Your hips should be at 90-100° as well, and your wrists should remain straight (neutral position) while typing — not bent up, down, or sideways.

Here's a quick self-check: (1) Feet flat on floor/footrest — no dangling; (2) Knees at ~90°, with 2-3 finger-widths space behind knees; (3) Hips slightly above knee level; (4) Lower back supported by lumbar curve; (5) Shoulders relaxed, not elevated; (6) Forearms parallel to floor when typing; (7) Eyes level with top of screen; (8) No forward head posture. If you check all 8, your setup is well-optimized!

Yes — the principles still apply. For standing: set the desk height so your elbows are at ~90° when typing, with forearms parallel to the floor. The screen top should remain at or slightly below eye level. For sit-stand desks, you'll need two ideal heights: one for sitting (with your chair) and one for standing. Our calculator focuses on seated setups, but the elbow-angle rule transfers directly to standing desk configuration.

If your desk is too high (common with fixed 75cm+ desks for people under 170cm): (1) Raise your chair until your elbows reach desk height comfortably; (2) Use a footrest to support your feet so knees stay at ~90°; (3) Ensure the footrest is wide enough for both feet; (4) If the desk is extremely high, consider a keyboard tray that mounts below the desk surface. Avoid the temptation to sit on a cushion — this reduces stability and often worsens posture.

Reassess your setup: (1) When you change desks or chairs; (2) When you get a new monitor or laptop; (3) If you experience any new aches, pain, or discomfort; (4) At least once every 6 months, as chair adjustments can drift over time; (5) After significant weight changes, which can affect your seated proportions. Many people benefit from a quick posture and setup check at the start of each workday.

Our recommendations are based on widely recognized ergonomic standards including: ANSI/HFES 100-2007 (Human Factors Engineering of Computer Workstations), ISO 9241 (Ergonomics of Human-System Interaction), OSHA guidelines for computer workstations, and anthropometric data from CDC/NASA populations. Calculations use standard body proportion ratios derived from ergonomic research. Always consult an ergonomics professional for personalized assessments, especially if you have pre-existing conditions.