How to Adjust an Office Chair in 7 Steps

To adjust an office chair, set the seat height first so your feet rest flat on the floor, then set the seat depth so there is a small gap behind your knees, fit the backrest to the curve of your lower back, and lower or raise the armrests until they barely touch your forearms with your elbows bent at about 90 degrees. Finally, check the chair against your desk: your elbows should be about level with the keyboard. The steps below follow guidance from OSHA, the Canadian Centre for Occupational Health and Safety (CCOHS) and UCLA’s ergonomics program. This guide is research-based and summarizes those sources; it is not a review of any specific chair.

This is general workstation setup information, not medical advice. If you have pain or an injury, ask a qualified health professional about your setup.

Before You Start

Find your chair’s controls before you sit down. Levers and knobs differ by model, so keep the manufacturer’s manual or product page handy. Most task chairs have some of these adjustments: seat height, seat depth (a sliding seat pan), backrest height or lumbar position, recline tension or lock, seat tilt and armrest height. If your chair is missing one, the table later in this guide covers workarounds.

Wear the shoes you usually work in, and set the chair at the desk you actually use. A chair adjusted in isolation often needs a second pass once you sit at the keyboard.

How to Adjust an Office Chair in 7 Steps

1. Set the seat height

CCOHS suggests starting while standing in front of the chair: adjust the height so the highest point of the seat, with the seat level, is just below your kneecap. Then sit down with your feet flat on the floor. OSHA describes the right height as one where the entire sole of your foot rests on the floor and the back of your knee sits slightly higher than the seat. If you have to raise the seat higher than that to reach your desk, you will need a footrest (step 6).

2. Set the seat depth

Sit all the way back so your lower back touches the backrest. OSHA says the seat pan should support most of your thigh without the front edge touching the back of your knee. The guides put the gap slightly differently:

• CCOHS: the space between the front edge of the seat and your calves should fit a clenched fist, about 2 inches.
• UCLA: a 1 to 2 inch space between the front edge of the seat and the back of your knees.

If your chair has a sliding seat pan, move it until you have that gap. OSHA notes that depth adjustment is what lets shorter users sit with their back fully supported, so a seat that is too deep and does not adjust can leave you choosing between the backrest and the gap behind your knees.

3. Fit the backrest and lumbar support

CCOHS advises moving the backrest forward and backward as well as up and down so it fits the hollow in your lower back. OSHA describes the same goal: the outward curve of the backrest should fit into the small of your back. UCLA adds that the backrest should support your spine from the top of the hips through the bottom of the shoulder blades. If your chair has a separate lumbar pad, move it up or down until it sits in that curve rather than above or below it.

4. Set recline tension and seat tilt

OSHA recommends a backrest that locks in place or has adjustable tension, so it gives your lower back enough resistance. Set the tension so the backrest supports you when you lean back but does not push you forward. UCLA describes a neutral seated posture as a slightly reclined position, so a fully upright lock is not required. CCOHS notes you can tilt the seat itself forward or backward if you prefer.

5. Adjust the armrests

CCOHS gives a simple method: sit upright with your arms hanging loosely at your sides, bend your elbows to about a right angle (90 degrees), and adjust the armrests until they barely touch the undersides of your elbows. OSHA’s goal is similar: armrests should support your lower arm while your upper arm stays close to your body. Two cases where you should take them off or stop using them:

• The armrests, even at their lowest setting, lift your elbows even slightly (CCOHS).
• The armrests bump the desk and keep you from pulling close enough to work (OSHA).

6. Match the chair to your desk

Now pull up to the desk. OSHA says your elbows should be about the same height as the keyboard and hang comfortably at your sides, with your shoulders relaxed and your wrists straight and in line with your forearms. If the keyboard is too high, raise the chair. If raising the chair means your feet no longer rest flat, add a footrest: OSHA recommends one when the seat cannot be lowered, and CCOHS says it should be adjustable and support both feet. This is common with desk converters, which our desk converter setup guide covers. If you use a height-adjustable desk, set the desk to your seated elbow height instead of moving the chair; our standing desk height guide explains how to measure it.

7. Check the base and casters

OSHA recommends a strong five-leg base with casters that let the chair move easily and that are appropriate for the type of flooring at your workstation. If the chair rolls too freely or drags, check whether the manufacturer offers casters for your floor type. Once everything is set, note your settings, especially if someone else shares the chair, and readjust whenever you change desks, shoes or monitor position.

Quick Reference: Office Chair Settings

If Your Chair Is Missing an Adjustment

What to Look For if You Are Buying a New Chair

If your current chair cannot reach the settings above, OSHA’s chair guidance lists features worth checking on a product page: adjustable seat height, a seat pan with depth adjustment, a seat wide enough for your hips, height-adjustable lumbar support, a backrest that reclines at least 15 degrees from vertical and locks or has tension control, adjustable armrests, and a five-leg base. Compare the listed seat height range with your own measurement from step 1 before you buy.

Sitting Is Only Part of It

Even a well-adjusted chair works best when you change position through the day. If you have a sit-stand desk, our guide on how long to stand at a standing desk summarizes the routines ergonomics programs suggest. When you sit back down, recheck that your elbows still line up with the keyboard.

Frequently Asked Questions

How high should my office chair be?

High enough that your feet rest flat on the floor with the back of your knee slightly higher than the seat, per OSHA. CCOHS suggests setting the top of the seat just below your kneecap while standing in front of the chair, then fine-tuning once seated.

How much space should be behind my knees?

CCOHS says about a clenched fist (roughly 2 inches) between the seat’s front edge and your calves; UCLA says 1 to 2 inches between the seat edge and the back of your knees. Either way, the seat edge should not press into the back of your knees.

Should my armrests touch my elbows?

Just barely. CCOHS recommends adjusting them until they barely touch the undersides of your elbows with your elbows bent at about 90 degrees. If they push your shoulders up even at the lowest setting, remove them.

What if my desk is too high for my chair?

Raise the chair until your elbows are about level with the keyboard, then use a footrest if your feet no longer rest flat on the floor. OSHA and CCOHS both recommend a footrest in this situation.

Should my office chair recline?

Some recline is fine. UCLA describes a slightly reclined position as part of neutral sitting posture, and OSHA recommends a backrest that can recline at least 15 degrees from vertical and lock or offer tension control.

Sources

• OSHA, Computer Workstations eTool: Chairs
• OSHA, Computer Workstations eTool: Keyboards
• Canadian Centre for Occupational Health and Safety, Office Ergonomics: How to Adjust Office Chairs
• UCLA Ergonomics, Selecting a Chair

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