Is an Under Desk Keyboard Tray Worth Installing

Your desk is 74 cm high, your chair is already as tall as it goes before your feet dangle, and your shoulders still creep up toward your ears by mid-afternoon. A keyboard tray promises to drop your hands to the right height without replacing the desk. Sometimes it does exactly that. Sometimes it steals your knee space, wobbles on every keystroke and leaves your mouse stranded on the desktop above.

I have fitted and removed more trays than I can count in ten years of ergonomic assessments. This is how to tell, before you drill anything, whether an under desk keyboard tray will help you or just add another thing to bump your knees on.

The height problem a keyboard tray solves

Most fixed desks are built at 72 to 76 cm. That height suits someone around 185 cm tall. For anyone shorter, the keyboard ends up above elbow height, so you either shrug your shoulders or bend your wrists upward to type. Over a full workday, both add up.

The target is simple: with your shoulders relaxed and elbows bent around 90 to 100 degrees, the home row of the keyboard should sit level with or slightly below your elbows. Measure it. Sit in your normal chair height, let your arms hang, bend at the elbow, and measure from the floor to the underside of your forearm. For many people of average height that comes out between 62 and 68 cm, a full 6 to 12 cm below a standard desktop.

A tray closes that gap. It mounts under the desk and holds the keyboard at a lower height, often with a tilt adjustment. Our explainer on why wrist position matters more than keyboard price goes deeper into the angles involved.

When an under desk keyboard tray is worth it

A tray is the right fix if most of these are true:

Your desk is fixed height and you cannot replace it.
Raising your chair would leave your feet unsupported, even with a footrest.
The gap between your elbow height and the desktop is 5 cm or more.
You have at least 60 cm of depth under the desk for your legs once the tray is fitted.
You use the keyboard for several hours a day, not just for quick replies.

If two or more of those are false, the tray is probably the wrong tool. The most common case: a tall person who already sits comfortably at a standard desk. They gain nothing and lose leg room.

Tray types compared

Type	Typical price	Adjustable	Main drawback
Fixed slide-out drawer	20 to 50	No	Height is set by the rail, often too shallow
Clamp-on tray	40 to 90	Limited	Can flex and bounce while typing
Articulating arm on a track	120 to 300	Height, tilt, swivel	Needs a solid underside to screw into

Prices are rough and in dollars or euros, the spread is similar in both. The cheap drawer style is what most people picture, and it is the one I see removed most often. It sits only 3 to 5 cm under the desktop, which rarely gets the keyboard low enough to matter.

The articulating arm is the one that actually solves the problem. A good one drops 10 to 15 cm below the desk, tilts to a negative angle, and slides away when you need the full desktop.

The mouse problem nobody mentions

Here is the part that most tray guides skip. If your keyboard drops 10 cm and your mouse stays on the desktop, you have fixed one arm and left the other in the old position. Your mouse shoulder keeps shrugging all day, often worse than before because the reach is now uneven.

Check that the tray is wide enough for both, at least 65 to 70 cm for a full-size keyboard plus a mouse area. Many trays sold as "keyboard trays" are only 50 cm wide. A compact keyboard without a number pad frees up about 9 cm, which is sometimes the difference between a tray that fits a mouse and one that does not.

A thin desk mat across the tray keeps the mouse surface consistent. Our guide to choosing a desk mat that actually protects your wrists lists the thickness that works on narrow surfaces.

Why negative tilt beats the keyboard feet

The standard advice is to flip out the little feet on the back of your keyboard so it slopes toward you. On a tray, I would do the opposite.

Raised feet bend your wrists upward, which is the position most associated with strain. A tray with a negative tilt of 5 to 10 degrees, meaning the back edge lower than the front, lets your wrists stay straight while your hands sit lower than your elbows. It feels odd for two or three days. After that, most people I work with say they cannot go back.

This only works on articulating trays. Drawer and clamp styles stay flat, which is one more reason the cheaper options tend to disappoint.

How to fit one in about 45 minutes

Measure the underside. You need a flat, solid area at least 55 cm deep for most tracks. Check for drawers, crossbars or a modesty panel in the way.
Check desk thickness. Most track screws are 16 mm long. Desktops thinner than 18 mm, common on cheap particleboard desks, need shorter screws to avoid poking through.
Mark the centre line where you sit, not the centre of the desk. Many people sit off to one side.
Pilot drill and fix the track with all supplied screws. Skipping two because they are hard to reach is how trays start to sag.
Set height and tilt with your normal chair height, using the elbow measurement from earlier.
Test for bounce. Type firmly for a minute. If the tray flexes visibly, tighten the arm joints before adjusting anything else.

When to skip the tray entirely

If you are close to replacing your desk anyway, a height-adjustable desk solves the same problem with no knee loss and lets you stand part of the day; see how long to stand at a standing desk each day if you go that way. If you are shorter and the desk is far too high, a raised chair plus a proper footrest is the cheapest fix, often under 40 in total. A tray earns its place mainly when the desk is staying and the chair has nowhere left to go.

Frequently asked questions

Are keyboard trays good for ergonomics?

They can be, if your desk is too high for your elbow height and the tray drops the keyboard low enough. Adjustable trays with negative tilt give the clearest benefit. Fixed drawer trays often sit too close to the desktop to make a real difference.

How low should a keyboard tray be?

The home row should sit level with or slightly below your elbows when your shoulders are relaxed and your arms are bent around 90 degrees. For many people that is 62 to 68 cm from the floor. Measure your own elbow height rather than relying on a chart.

Can you put a mouse on a keyboard tray?

Yes, and you usually should, so both arms work at the same height. Choose a tray at least 65 to 70 cm wide, or use a compact keyboard to free space. Leaving the mouse on the desktop while the keyboard drops often causes shoulder strain on the mouse side.