Measuring a desk before buying any equipment

Start with the screen, not the hardware

Sit as you normally do, then measure where your eyes land on the panel. If the top edge is below eye level you are looking down all day, and no keyboard change fixes that. A stack of books makes a quick test before any arm is bought.

The panel wants to be roughly an arm away, with the top of the screen near eye level. That single position decides the height of the arm, the depth of the desk and whether a light bar has somewhere to clip.

The four numbers worth writing down

Take these before ordering anything, because returns are tedious and a desk is hard to move once it is loaded.

• Desk depth and the clear width between the legs, which caps how wide the keyboard can be.
• Desk edge thickness at the back, which decides whether a clamp fits at all.
• Wall clearance behind the desk, because an arm sweeps backwards as the screen comes forward.
• Height from floor to desktop, which sets the seat height and where your elbows rest.

Then place the light and the inputs

Light should fall on the desk from above and in front, not from behind your shoulder, where it reflects off a glossy panel. A bar clipped to the top edge lands in that position by default, which is why it works where a desk lamp often does not.

Keyboard and mouse are about width and reach: the mouse should sit within a relaxed arm, not beyond it. If the desk is too narrow for both, a narrower keyboard buys more room than a smaller mouse does.

• Mount the light so the beam lands on the desk, not on the panel surface.
• Keep the mouse inside the arc the forearm reaches without leaning.
• Leave slack in every cable so the desk can be pulled out for cleaning.