You've invested in an ergonomic chair—but are you actually getting the ergonomic benefits? A surprising number of people purchase high-quality seating only to use it with incorrect settings, essentially paying premium prices for mediocre results. Your chair might have a dozen adjustment mechanisms, but if they're not configured for your specific body, you're not experiencing true ergonomic support. This guide walks you through adjusting every aspect of your chair for optimal comfort and spinal health.
Before You Begin
Gather a few things before starting your adjustment session. Have your desk and computer set up as you normally use them—you'll need to fine-tune chair settings in relation to your actual work surface. Wear the type of footwear (or lack thereof) you typically use while working. And allow about 15-20 minutes for the process; rushing through adjustments rarely produces optimal results.
If your chair came with a manual, keep it handy for reference on which levers and knobs control which functions. Chair adjustment mechanisms aren't always intuitive, and many a frustrated user has wondered why their "broken" lumbar support won't adjust—only to discover they were pulling the wrong lever.
Step 1: Seat Height
Seat height is the foundation of all other adjustments, so start here. Sit in the chair with your feet flat on the floor (or on a footrest if you'll be using one). Your thighs should be parallel to the floor or angled very slightly downward—never upward. Your knees should bend at approximately 90 degrees.
The standard adjustment method is a pneumatic lever, typically located under the right side of the seat. Lift it while seated to lower the chair (your weight compresses the gas cylinder); stand slightly and lift it to raise the chair. Some chairs have button-activated adjustments instead of levers.
If you can't achieve both correct foot position AND proper arm-to-desk relationship, prioritise the desk relationship and add a footrest. Your arms at the desk determine repetitive strain risk on wrists and shoulders; your feet can be supported externally.
Step 2: Seat Depth
Seat depth affects how well the backrest supports your spine. With your back against the lumbar support, check the gap between the front edge of the seat and the back of your knees. Ideally, you should have 5-10cm (about 2-4 finger widths) of clearance. If the seat edge presses into the back of your knees, it restricts circulation; if there's too much gap, you're probably not getting proper backrest contact.
Not all chairs offer seat depth adjustment. Those that do typically have one of two mechanisms: a sliding seat pan (you can push the entire seat forward or back relative to the backrest) or a sliding backrest (the back moves forward or back relative to the seat). Check for a lever or button under the front or side of the seat.
Step 3: Lumbar Support
This is arguably the most important adjustment for preventing back pain. Your lumbar support should fill the natural inward curve of your lower back, located roughly at belt height (the L3-L4 vertebrae region for most people). When properly positioned, you should feel gentle, consistent pressure against your lower back—enough to prevent slouching without being uncomfortable.
Height Adjustment
Many ergonomic chairs allow you to raise or lower the lumbar support to match your specific spinal curve. This might be a sliding mechanism on the backrest, a knob, or a lever. Adjust until the most prominent part of the lumbar support aligns with the deepest part of your lumbar curve.
Depth Adjustment
Higher-end chairs also offer depth (or firmness) adjustment, controlling how far the lumbar support protrudes into your back. Start with moderate depth and increase or decrease based on comfort. Too little depth and you won't get adequate support; too much feels intrusive and can push you away from the backrest.
- Support positioned at the small of your back (roughly belt height)
- Gentle pressure that maintains your natural spinal curve
- Back resting against the support—not hovering away from it
- Able to maintain position without conscious effort
- Comfortable after 30+ minutes of use
Step 4: Backrest Recline
Sitting perfectly upright at 90 degrees isn't natural or comfortable for extended periods. Research suggests a slightly reclined position of 100-120 degrees reduces spinal disc pressure and muscle strain. However, you also need to be able to work effectively at your desk.
Most ergonomic chairs offer several recline options:
- Recline angle: How far back the chair tilts
- Tension control: How much resistance you feel when leaning back
- Tilt lock: The ability to lock the backrest at a specific angle
For focused desk work, a slight recline of 100-110 degrees with the tilt locked works well. For reading or thinking tasks, you might unlock the tilt and allow gentle rocking. Adjust the tension so that reclining requires slight effort but isn't a battle—the chair should support you in a reclined position without pushing you back upright immediately.
Step 5: Armrest Height
Properly positioned armrests reduce strain on your shoulders, neck, and upper back by supporting the weight of your arms. When typing or using a mouse, your armrests should be at roughly the same height as your desk surface, allowing your elbows to rest at approximately 90 degrees with your shoulders relaxed.
If armrests are too high, you'll hunch your shoulders up to reach them. If too low, you'll slump sideways or not use them at all, leaving your arms unsupported. Height adjustment is typically via buttons on the sides of the armrests or a lever underneath.
Step 6: Armrest Width and Depth
Many ergonomic chairs offer 3D or 4D armrests that adjust in multiple directions. Width adjustment (moving armrests closer together or further apart) allows you to position them directly under your elbows, regardless of your shoulder width. Depth adjustment (sliding armrests forward or back) helps when alternating between tasks requiring different arm positions.
For keyboard work, position armrests so your forearms are parallel and your elbows are close to your body—not splayed outward. If your armrests are getting in the way of your desk, you may need to adjust their position or angle them slightly outward.
Step 7: Headrest (If Applicable)
Not all ergonomic chairs include headrests, and they're not essential for everyone. If your chair has one, adjust it to support your head in a reclined position without pushing your head forward when sitting upright. The headrest should contact the back of your head, not your neck, when you lean back.
For focused forward-facing work, a headrest is largely irrelevant—you're not leaning back. It becomes valuable for video calls, reading on screen, or during thinking breaks when you want to recline without straining your neck.
Setting and forgetting: Your ideal settings may change over time or with different tasks. Periodically reassess, especially if discomfort develops. Also avoid over-adjusting—making multiple changes simultaneously makes it impossible to know what's helping or hurting.
Fine-Tuning Over Time
Initial adjustments are a starting point, not a final destination. Use your new settings for several days, paying attention to how your body feels. Some discomfort during the first day or two is normal as your body adapts, but persistent pain suggests something needs tweaking.
Make one adjustment at a time and give it at least a day before changing something else. This methodical approach helps you identify exactly what helps and what doesn't. Keep notes if needed—"Lumbar depth at 3, comfortable after 4 hours" is more useful than vague memories when troubleshooting later.
Remember that even perfect chair adjustment is only part of ergonomic health. Pair your well-adjusted chair with regular movement breaks, good monitor positioning, and attention to your overall workspace setup. For a complete guide to workspace ergonomics, see our article on setting up the perfect ergonomic home office.