How to Adjust an Ergonomic Chair: A Step-by-Step Setup Guide

How to Adjust an Ergonomic Chair: A Step-by-Step Setup Guide

An ergonomic chair can have multiple adjustment features, but those features only help when they are set to suit your body, desk and daily tasks.

Two people can use the same chair and have very different experiences. One person may feel well supported, while another may notice pressure behind the knees, tense shoulders or an uncomfortable lower back. In many cases, the difference comes down to how the chair has been adjusted.

The aim is not to force your body into one rigid “perfect posture”. A good chair setup should support comfortable movement, help you reach your keyboard and mouse without strain, and allow you to change position throughout the day.

This guide explains how to adjust an ergonomic chair step by step, starting with the seat and finishing with the complete workstation.

Before You Start: Sit at Your Usual Desk

A chair should not be adjusted in isolation.

Sit at the desk where you normally work, with your keyboard, mouse and monitor in their usual positions. The correct chair height depends partly on the height of the work surface.

Before adjusting the chair:

• Wear the shoes you normally wear while working.
• Sit fully back in the seat.
• Place the keyboard and mouse within comfortable reach.
• Make sure there is enough clearance beneath the desk.
• Familiarise yourself with the chair controls.

WorkSafe Victoria recommends adjusting the chair and desk together so that the working surface is around elbow height. Where the desk is too high and cannot be lowered, the chair may need to be raised and a footrest used to support the feet.

Step 1: Adjust the Seat Height

Start with the seat height because it affects almost every other adjustment.

Sit with your back against the backrest and adjust the chair until:

• Your feet are supported by the floor or a footrest.
• Your thighs feel comfortably supported.
• Your knees are approximately level with, or slightly lower than, your hips.
• There is no excessive pressure underneath your thighs.
• Your shoulders remain relaxed when using the keyboard and mouse.

Your knees and elbows do not need to remain at an exact 90-degree angle. Treat a right angle as a general starting point rather than a strict rule.

Signs the seat is too high

The seat may be too high when:

• Your feet do not reach the floor.
• You feel pressure underneath your thighs.
• You sit towards the front edge of the chair.
• Your legs feel numb or uncomfortable.
• You need to point your toes downward for support.

Lower the chair where possible. When the desk is too high to allow this, raise the chair to the correct working height and use a stable footrest.

Signs the seat is too low

The seat may be too low when:

• Your knees sit noticeably higher than your hips.
• Your hips feel compressed.
• You lean forward to work.
• Your shoulders lift when typing.
• It is difficult to stand up comfortably.

Raise the chair gradually until your legs feel supported and you can work without lifting your shoulders.

Step 2: Adjust the Seat Depth

Seat depth controls how much of your thighs are supported.

Sit fully back so your lower back remains against the backrest. Check the distance between the front edge of the seat and the back of your knees.

Aim to leave approximately two to three finger widths of space.

When the seat is too deep

A seat may be too deep if:

• The front edge presses into the back of your knees.
• You cannot use the backrest without pressure behind the legs.
• You slide forward in the seat.
• You sit with your back rounded away from the backrest.

Slide the seat pan backwards, or move the backrest forward if your chair uses that type of adjustment.

When the seat is too shallow

A seat may be too shallow if:

• Only a small section of your thighs is supported.
• You feel concentrated pressure under your sitting bones.
• Your legs fatigue quickly.
• The seat feels noticeably too small for your body.

Slide the seat forward while keeping enough clearance behind the knees.

Not every office chair has adjustable seat depth. In that case, the fixed seat dimensions need to match your leg length reasonably well.

Step 3: Position the Lumbar Support

Lumbar support should follow the natural inward curve of your lower back.

It should generally sit around waist level rather than pressing into the upper back or the tailbone.

Adjust the lumbar support until:

• It makes comfortable contact with your lower back.
• It supports rather than sharply pushes.
• You can sit fully against the backrest.
• Your upper body does not feel forced forward.
• The support remains comfortable when you change posture.

WorkSafe Victoria advises adjusting the backrest so its curve fits the lower back around waist level. A slight backward tilt can also open the hip angle and reduce load on the lumbar area.

If the lumbar support feels too strong

Reduce its depth or tension where possible.

If the support is height-adjustable, also try moving it slightly lower or higher. A lumbar pad in the wrong position can feel more intrusive than one with excessive depth.

If you cannot feel the lumbar support

Try:

• Moving it upward or downward.
• Increasing its depth.
• Sitting fully against the backrest.
• Reducing the seat depth if the seat prevents you from reaching the backrest.

Lumbar support is important, but it works together with seat height, seat depth and backrest angle. It should not be treated as the only important chair adjustment.

Step 4: Adjust the Armrests

Armrests should lightly support your forearms without lifting your shoulders.

Set them so that:

• Your shoulders stay relaxed.
• Your elbows remain close to your body.
• Your forearms receive light support.
• Your wrists stay in a neutral position.
• The chair can move close enough to the desk.

Armrests do not have to line up exactly with the desktop.

In fact, armrests that are too high, too long or too wide may hit the desk and stop you from sitting close enough to your keyboard. WorkSafe Victoria notes that armrests can reduce load on the shoulders and back during rest, but they may interfere with desk positioning if they cannot be adjusted appropriately.

Armrests are too high when:

• Your shoulders rise towards your ears.
• Your elbows are pushed outward.
• You cannot relax your upper body.
• The armrests press against the desk.

Lower them until they barely support your arms.

Armrests are too low when:

• Your arms hang without support.
• You lean to one side.
• You drop one shoulder.
• You reach downward to use them.

Raise them carefully, but do not use the armrests to hold your shoulders up.

Adjusting multidirectional armrests

If your chair includes armrests that move forward, backward, inward or outward:

• Bring them closer for keyboard work.
• Move them slightly wider if they press against your body.
• Slide them back when you need to move closer to the desk.
• Angle them inward only when this follows the position of your forearms.

Your arms should rest naturally rather than being forced into the position of the armrests.

Step 5: Set the Backrest Angle

Many users assume that sitting completely upright is always best. In practice, a slightly reclined position can often feel more comfortable and supported.

For focused keyboard work, begin with the backrest relatively upright but not forcing your torso forward.

For reading, calls or breaks, recline slightly while keeping your back supported.

The correct position is one that allows you to:

• See the screen comfortably.
• Reach the keyboard without leaning.
• Keep your lower back against the backrest.
• Change posture without fighting the chair.

Avoid sitting on the edge of the seat while leaving the backrest unused.

Step 6: Adjust the Recline Tension

Recline tension controls how much resistance you feel when leaning backwards.

It is different from a recline lock.

• Recline tension controls how easy or difficult it is to lean back.
• Recline lock holds the backrest at a selected position.
• Backrest angle adjustment changes the resting angle of the backrest.
• Synchro-tilt allows the seat and backrest to move together at a designed ratio.

Turn the tension control gradually.

The setting is appropriate when:

• You can recline without using excessive force.
• The chair does not fall backwards unexpectedly.
• The backrest follows your movement smoothly.
• You can return upright without pulling yourself forward.

If the chair tips backwards too easily, increase the tension. If it feels rigid and difficult to move, reduce it.

Heavier users will generally need more tension, while lighter users may need less.

Step 7: Position the Headrest

A headrest is mainly intended to support the neck or the base of the skull during reclining.

It does not need to remain in contact with your head while you are actively typing.

Adjust it so that:

• It supports the upper neck or base of the skull.
• It does not push your head forward.
• Your chin remains in a natural position.
• You can recline comfortably.
• It does not interfere when sitting upright.

If the headrest pushes the centre of your head forward, move it backwards, change its angle or lower it.

A chair without a headrest can still be suitable for ergonomic work. Headrests are most useful for people who recline frequently, take calls or spend time reading from the screen.

Step 8: Check Your Position Against the Desk

Once the chair itself has been adjusted, check how it works with the desk.

Your setup should allow you to:

• Sit close to the work surface.
• Keep your elbows near your body.
• Reach the keyboard and mouse without extending your arms.
• Keep your wrists relatively straight.
• Avoid lifting your shoulders.
• Maintain clear space for your knees and thighs.

If the chair feels comfortable but your shoulders still rise while typing, the desk or keyboard may be too high.

If your arms reach forward, bring the keyboard and mouse closer.

If the armrests prevent you from approaching the desk, lower, shorten or move them backwards.

Step 9: Adjust the Monitor Last

Set the monitor only after the chair and desk heights have been established.

WorkSafe Victoria recommends adjusting computer screens after chair and desk height have been set.

Position the screen so that:

• It is directly in front of your main working position.
• You do not need to twist your neck.
• The text is comfortable to read without leaning forward.
• The screen height allows your head to remain balanced.
• Frequently used windows appear near the centre of your view.

For a laptop used for long periods, consider a separate keyboard and mouse so the screen can be raised independently.

Step 10: Save Your Preferred Settings

Some ergonomic chairs include memory settings or clearly marked adjustment levels.

Once you find a comfortable setup:

• Note the seat height.
• Record the seat-depth position.
• Remember the lumbar level.
• Mark the preferred recline tension.
• Photograph the control positions if the chair is shared.

This is especially useful in hot-desking environments or shared home offices.

Even after saving your settings, small adjustments may be needed for different tasks.

Common Ergonomic Chair Problems and How to Fix Them

My feet do not reach the floor

Likely cause: The chair is too high because the desk is too high.

Try: Lower the chair where possible. Otherwise, keep the chair at the correct keyboard height and add a footrest.

I feel pressure behind my knees

Likely cause: The seat is too deep or too high.

Try: Reduce the seat depth, lower the seat slightly or check that you are sitting fully back.

My lower back feels pushed forward

Likely cause: The lumbar support is too strong, too high or incorrectly positioned.

Try: Reduce the lumbar depth or move it until it follows the curve around waist level.

I cannot feel the lumbar support

Likely cause: It is too low, too high or too far behind you.

Try: Reposition it, increase its depth or reduce the seat depth so you can sit closer to the backrest.

My shoulders feel tense

Likely cause: The armrests or desk may be too high.

Try: Lower the armrests and check whether the keyboard surface allows your shoulders to remain relaxed.

My wrists bend upward while typing

Likely cause: The keyboard is too high or too far away.

Try: Lower the chair–desk working height where possible and move the keyboard closer.

The headrest pushes my head forward

Likely cause: The headrest is too far forward or incorrectly angled.

Try: Move it backwards, change the angle or position it beneath the base of the skull.

The chair reclines too easily

Likely cause: The recline tension is too loose.

Try: Increase the tension gradually.

The chair feels too rigid when leaning back

Likely cause: The tension is too tight or the recline is locked.

Try: Release the lock and reduce the tension.

I keep leaning forward

Likely cause: The screen, keyboard or mouse may be too far away, or the lumbar support may not be contacting your back.

Try: Move the work equipment closer and check the seat depth and backrest position.

How Often Should You Change Position?

A well-adjusted chair does not remove the need to move.

There is no single sitting posture that should be held for the entire day. WorkSafe Victoria notes that changing seated positions is desirable and that no chair can provide a perfect position for long periods. It also recommends getting up regularly and making small adjustments when tasks change.

During the day:

• Shift between upright and slightly reclined positions.
• Stand up regularly.
• Walk during natural breaks.
• Change the chair angle for different tasks.
• Avoid staying fixed in one posture simply because it appears “correct”.

Comfortable movement is part of good ergonomics.

What If Your Chair Does Not Have Every Adjustment?

For lighter everyday use, you can also compare Shappa’s range of office chairs for home and workplace setups.

A chair does not need every possible mechanism to be comfortable.

A simpler office chair may work well when its fixed dimensions already suit your body and desk. A highly adjustable ergonomic chair provides more flexibility, especially when:

• Several people use the chair.
• The user is taller or shorter than average.
• The chair is used for long workdays.
• Different working postures are preferred.
• The workstation changes frequently.
• More precise lumbar, arm or seat support is needed.

The number of adjustment points matters less than whether the available adjustments allow the chair to fit the user properly.

When the Chair May Be the Wrong Size

Adjustment cannot compensate for every fit problem.

The chair may not be suitable when:

• The seat remains too deep at its shortest setting.
• The seat is too narrow or too wide.
• The gas lift cannot reach the required height.
• The lumbar support cannot align with your lower back.
• The armrests remain too far apart.
• The backrest pushes your shoulders forward.
• The desk clearance prevents correct positioning.

In these situations, consider a different chair size or configuration rather than continually trying to adapt your posture to unsuitable furniture.

A Quick Ergonomic Chair Setup Checklist

Before starting work, check that:

• Your feet are supported.
• Your thighs feel comfortable.
• There is a small gap behind your knees.
• Your lower back contacts the lumbar support.
• Your shoulders remain relaxed.
• Your elbows stay near your body.
• The armrests do not block the desk.
• The headrest does not push your head forward.
• The recline moves with controlled resistance.
• Your keyboard and mouse are close.
• Your monitor is positioned after the chair and desk.
• You can change posture easily.

The setup does not need to look identical for every person. The goal is a stable, comfortable working position that supports movement.

Frequently Asked Questions

What should I adjust first on an ergonomic chair?

Start with seat height, followed by seat depth and lumbar support. Then adjust the backrest, armrests, recline tension and headrest. Finish by checking the desk, keyboard, mouse and monitor.

Should my knees be exactly 90 degrees?

No. Around 90 degrees can be a useful starting point, but exact angles are not required. Your feet should be supported, your thighs should feel comfortable, and your knees should generally be level with or slightly lower than your hips.

How much space should be behind my knees?

Aim for approximately two to three finger widths between the seat edge and the back of your knees. There should be enough clearance to avoid pressure without sacrificing too much thigh support.

Should armrests be level with the desk?

Not necessarily. They should support your forearms while keeping your shoulders relaxed and allowing the chair to move close to the desk. Armrests that hit the desktop may need to be lowered or moved backwards.

Should the headrest touch my head while typing?

Usually not. A headrest is primarily useful when reclining. It should support the upper neck or base of the skull without pushing the head forward.

Is it better to sit completely upright?

Not all the time. A supported, slightly reclined position may be comfortable for many tasks. The best approach is to alternate between supported positions rather than holding one rigid posture.

Why does my new ergonomic chair feel uncomfortable?

The chair may not yet be adjusted to your body, or its dimensions may not suit you. Check seat height, depth, lumbar position and desk compatibility before deciding whether the chair itself is unsuitable.

How long does it take to get used to a new ergonomic chair?

Some users feel comfortable immediately, while others need several days of small adjustments. A new chair may feel unfamiliar, but it should not cause sharp pain, numbness or increasing discomfort.

Can an ergonomic chair prevent back pain?

An ergonomic chair may improve support and help reduce awkward working positions, but it cannot guarantee that pain will be prevented or treated. Movement, workstation layout, work habits and individual health factors also matter.

Final Thoughts

Learning how to adjust an ergonomic chair is just as important as choosing the chair itself.

Begin with the seat height and depth, then position the lumbar support, armrests, backrest, recline tension and headrest. After that, adjust the desk equipment around your seated position.

A correct setup should not force you into one rigid pose. It should help you work comfortably, move naturally and change position throughout the day.

Explore the Shappa ergonomic chair collection to compare chairs with different adjustment ranges, support systems and workstation features.