How to Sit Properly in an Office Chair

The Five-Point Setup

Work through the points in order. Each adjustment shifts the position the next one is measured from, so armrests set before seat height have to be redone once the seat moves.

1. Seat Height

Sit with both feet flat on the floor. Knees sit at or slightly below hip height, and thighs are roughly parallel to the floor. If the desk is fixed-height and too tall for that position, raise the chair to the desk and use a footrest to support the feet.

2. Seat Depth

With the back against the backrest, two to three fingers should fit between the front edge of the seat and the back of the knee. A gap that is too small presses the seat edge into the leg. A gap that is too large leaves the thighs without support from the seat. A seat depth slider makes this a direct adjustment. On a chair without a slider, a firm cushion or rolled towel behind the lower back moves the hips forward and shortens the effective depth, at the cost of pushing any lumbar support away from the spine, so use it as a short test. The seat depth guide covers how to measure the depth needed.

3. Lumbar Support

The lumbar curve should meet the small of the back, roughly at the beltline. On a chair whose lumbar support is height-adjustable, raise or lower it until the contact point sits there, then sit back normally and check that contact holds when the body relaxes into the seat. If contact fades, the lumbar depth or the seat depth may need another look.

4. Armrests

Elbows rest at roughly 90 degrees with the shoulders relaxed and the forearms level with the desk surface. If the armrests cannot go low enough to keep the shoulders down, removing them (where the chair allows) or lowering the chair is a way to test whether they are the source of shoulder tension.

5. Monitor and Recline

The top of the screen sits near eye level, about an arm’s length away. Recline does not need to be locked at one angle. The recline angle guide covers the 100 to 120 degree range, and shifting position within it through the day suits a chair with a tilt mechanism.

Common Mistakes

• Perching forward off the backrest. A seat that is too deep for the sitter’s legs can cause this, as the sitter scoots forward to keep the front edge off the back of the knees.
• Crossing the legs for long stretches. This shifts the pelvis and can move the back away from the lumbar contact point.
• Leaning into one armrest. Check that both armrests are level before treating it as a posture habit.
• Never readjusting. Desk height, shoes, and body weight can all change what the right settings are. Recheck the five points from time to time, and after any change to desk, shoes or chair. If the chair has started sinking, how to fix an office chair that sinks and how long office chairs last cover that case.

When the Chair Itself Limits the Setup

Setup works within the chair’s adjustments. A chair with no seat depth slider, a fixed lumbar curve, or armrests that move in only two directions has a ceiling on how closely it can be fitted, and that ceiling belongs to the chair. Spec pages list which adjustments a given model has.

If discomfort continues after a couple of weeks with all five points set, the next step depends on where it shows up. Best Office Chairs for Back Pain covers chairs for lower back discomfort. The chair finder tool narrows options by body size and budget in a few questions, and the office chair buying guide covers the wider buying decision. Pain that persists or spreads, or that comes with numbness or tingling, is a reason to see a clinician, since adjusting a chair does not diagnose or treat a medical problem.

Frequently Asked Questions