Ergonomic desk height: how to work it out from your elbows

The ergonomic desk height is the one that puts your keyboard at about elbow height while you sit with your shoulders relaxed and your forearms roughly level. For most people that means the desk surface sits just below the elbow, and it is a number you measure on yourself, not one you read off a chart.

Most ready-made desks are built at roughly 28 to 30 inches (about 71 to 76 centimeters) high, and plenty of people, shorter people especially, find that too tall. If yours doesn't adjust, you can usually bring yourself to it instead, with a higher chair and something under your feet.

How to find your desk height in two minutes

The desk is measured from your body, and your body is measured from the chair, so the chair comes first.

1. Set the chair. Sit all the way back. Adjust the seat until your feet are flat on the floor, your thighs are roughly level and your knees are at about hip height or a little lower. Ignore the desk for now.
2. Let your arms hang. Drop your shoulders and let your upper arms hang loosely by your sides.
3. Bend your elbows. Bring your forearms up until they are about level with the floor, so your elbows sit at a right angle or slightly more open. Keep your wrists straight.
4. Measure. Have someone measure from the floor to the underside of your forearm, just in front of the elbow. On your own, sit side-on to a door frame, put a strip of tape on it at elbow height, then stand up and measure to the tape.
5. Allow for the keyboard. That number is where your keys should be, or a touch below. A slim keyboard like Apple's Magic Keyboard adds very little, so the desk can sit just under your elbows. A thick keyboard adds more, so the desk has to be lower to match.

Then sit at the desk with your hands on the keys and check three things. Your shoulders are down, not lifted. Your elbows are close to your sides, not pushed forward or out. Your wrists are straight, not bent up toward you. If all three hold, the height is right for you, whatever the tape says.

Check your legs too. Your thighs should fit under the desk with a little room to spare, and your knees shouldn't hit a drawer or a crossbar.

One thing the desk doesn't settle is the screen. A desk set for your elbows is almost always too low for your eyes, so a display or a laptop on it usually needs lifting. How high your monitor should be covers that half.

What height should a desk be for your height?

You'll find charts online that turn your height into a desk height. They are a fair starting point if you are shopping, but they can be off for you in particular. Two people of the same height can have elbows at quite different heights, because one has longer legs and the other a longer body. The chart also doesn't know which chair you sit in or what shoes you wear.

So use a chart to narrow down what to buy, and your elbows to set it up. A few rules of thumb help when choosing:

• Shared desks need to adjust. If more than one person works at it, an adjustable desk is the only kind that fits everyone.
• Slightly too high beats too low. A desk a little above your measurement can be fixed by raising the chair and adding a footrest. A desk that is too low needs lifting, which is more work and harder to do safely.
• Measure in the chair you'll use. A new chair with a different seat height changes the answer.

Sitting vs standing desk height

The rule is the same standing up: elbows at about a right angle, forearms roughly level, shoulders relaxed, keys at or just below elbow height. Measure while wearing the shoes you'll wear at the desk, or standing on your mat if you use one, because both change the number.

If your desk has memory buttons, save both heights so switching takes one press. On a manual desk, mark each height on the leg with tape. Standing desk tips covers how long to stand and how to build up to it.

What if your desk is too high?

This is the most common problem, and the easiest to fix, because you can bring yourself up to the desk instead of bringing the desk down.

1. Raise the chair until your elbows are level with the keys.
2. Support your feet. If they no longer reach the floor, put something firm under them: a footrest, a sturdy box, a couple of thick books or a ream of paper. Feet flat, thighs roughly level.
3. Check your thighs still fit. If raising the chair jams your thighs against the underside of the desk, the chair can't go that high, and you need the next fix instead.
4. Add a keyboard tray. A tray mounted under the desktop brings the keyboard down to elbow height without moving the chair. Choose one wide enough for the mouse or trackpad as well, or you'll be reaching up to the desk for it all day.
5. Look at the legs. Some desks have legs with more than one setting, or feet that screw in and out. Check before you assume a desk is fixed.
6. Lower the armrests if they bump the desk edge and stop you pulling in close.

A desk that is too high shows up first in the shoulders, which rise to lift your hands to the keys. Why your shoulders creep up at the desk explains the rest of that chain.

What if your desk is too low?

A low desk is less common, but tall people meet it often, and so does anyone working at an old desk or a low table. The signs are a rounded back, hands drifting below the elbows and thighs pressed against the underside.

• Use risers. Furniture or bed risers under each leg lift a desk evenly. Make sure they are made for the weight, that each leg sits squarely in its riser, and that the desk doesn't wobble when you lean on it.
• Lower the chair a little, if your feet can stay flat and your knees don't end up well above your hips.
• Don't hover. Holding your hands up above a low keyboard tires the shoulders as fast as reaching up to a high one.
• Move the screen separately. Raising a low desk raises the screen too, which helps, but check its height again afterwards.

If a desk can't be lifted safely, treat it as a short-term desk and move to a better surface for long sessions. A kitchen counter can work for standing spells.

Signs your desk height is wrong

Your body usually tells you before a tape measure does.

Keeping the height you set

A desk height, once set, mostly stays put. The things around it don't. Someone else lowers the chair, an older chair slowly sinks through the day, the footrest gets kicked under the desk, and by late afternoon you are perched on the front of the seat with your shoulders up.

That slow slide is what the Posture characters in Notchpals are for. They sit up in the notch and lean out a few times a day with one quick check. If Sir Pounce, the posh cat, is your Posture pick, some of those checks are aimed squarely at the kicked-away footrest:

Sir PounceFeet flat on the floor. Nobility keeps four paws down. Two will do.

The other repeating Posture visit is Shoulders down. On a desk that is a little too high for you, that is the one that catches the problem:

Sir PounceYour shoulders are up by your ears. Leave the ears to me. Mine are finer.

Sir Pounce has no idea how tall your desk is and can't see you, so treat each visit as a ten-second audit: feet supported, elbows by your sides, keys level with your elbows. Press Done once you've put things back.

Desk height can ease everyday stiffness, but it can't fix an injury. Pain that lasts, or pins and needles in your hands or arms, is a reason to see a doctor or a physiotherapist, not to move the desk again.