Proper typing posture: how to sit and set up your desk

Sit back in a chair that supports your lower back, with your feet flat and your thighs roughly level. Put the keyboard straight in front of you at elbow height, so your shoulders relax, your elbows stay close to your body, bent between 90 and 120 degrees, and your wrists stay straight. Set the screen 50 to 100 cm (20 to 40 in) away with its top at or just below eye level. Then change position often: no posture stays good for hours.

Try your setup on the typing test

Elbows close to your body, bent between 90 and 120 degrees, at about the height of the keyboard.
Wrists straight and in line with your forearms: not bent up, down or to the side.
Top of the screen at or slightly below eye level, so you look straight ahead or a little down.
Screen 50 to 100 cm (20 to 40 in) from your eyes, straight in front of you.
Back supported by the backrest, upright or leaning back slightly.
Feet flat on the floor or a footrest, thighs roughly level, knees at about hip height.

Upright sitting, one of the four neutral postures OSHA describes: the numbers match the checks above.

Set it up in this order

Chair height first. Raise or lower the seat until your feet are flat and your thighs roughly level. If the desk cannot move and the chair has to go up, put your feet on a footrest.
Keyboard at elbow height, straight in front of you, close enough that your elbows stay at your sides. If the desk is too high for that, raise the chair and use a footrest, or fit a keyboard tray.
Keyboard feet: use them only if they keep your wrists straight. Raised feet tilt the keyboard and can bend your wrists upward.
Mouse next to the keyboard, at the same height, so you do not reach for it.
Screen last: straight in front of you, at least 50 cm (20 in) away, its top at or slightly below eye level and its center about 15 to 20 degrees below. Turn it side-on to windows to avoid glare. If you wear bifocals, set it lower and tilt it up.

Your wrists while you type

Keep your wrists straight, in line with your forearms. A keyboard that is too low makes you type with your wrists bent up; one that is too high makes you lift your shoulders. Do not lean your forearms on a hard desk edge or a wrist rest with a sharp edge: the pressure can make your fingers tingle, like hitting your funny bone.

On a laptop

A laptop joins the screen to the keyboard, so if the keyboard is at elbow height, the screen is too low, and if the screen is at eye level, the keyboard is too high. For long sessions, raise the laptop to put its screen at the right height and use a separate keyboard and mouse at elbow height.

Move, and rest your eyes

Even a good posture is unhealthy if you hold it for hours. Change position through the day: adjust the chair or backrest a little, stretch your fingers, hands and arms, stand up and walk for a few minutes. OSHA suggests a five-minute break from the computer every hour, and resting your eyes now and then by looking at something about 6 m (20 ft) away.

At a gaming desk

The same rules hold. A low sensitivity needs room to sweep the mouse at elbow height, so check the width your sweep takes on the mouse pad size page before you push the keyboard aside, and keep the screen straight ahead rather than off to one side.

Check it in one minute

Shoulders relaxed, not lifted?
Elbows at your sides and level with the keyboard?
Wrists straight while you type?
Feet flat and back against the backrest?
Screen straight ahead, about an arm's length away, its top at eye level or just below?

Posture is half of comfortable typing; the other half is where your fingers rest: see touch typing. For the mouse hand, see mouse grips.

Sources: OSHA, Computer Workstations eTool: Good working positions, Keyboards, Monitors and Chairs.