If your feet dangle, start here

What happens when you raise the chair

Raising the chair until your forearms are level with the keyboard is the correct move on a desk that is too tall. It also lifts your feet off the floor, or leaves them touching with no weight through them.

What people do next is predictable: they perch forward onto the front edge of the seat so their feet reach, which means they are no longer using the backrest they paid for. Then they shift, and re-cross their legs, and shift again, all afternoon. The chair gets blamed for this. The chair is fine.

The free version

A ream of printer paper is about two inches. A shoebox is about four. Stack whatever you have under your feet until they rest flat with your thighs roughly parallel to the floor, then work a full day like that.

Two things come out of this. You find out whether foot support is actually your problem, and you learn the height you need — which is the number you cannot get from a product listing.

What to look for

• Adjustable height, covering the number you measured. Fixed-height footrests are a guess at your body.
• A tilted surface. A slight angle is more comfortable than flat for most people, and lets you shift position without losing support.
• Enough width to move. Your feet do not stay in one place for eight hours, and a narrow platform means half your shifts land on the floor.
• Weight or grip. A footrest that slides away every time you push on it is worse than the shoebox.

When you don't need one

If your feet already rest flat with your forearms level at the keyboard, your desk height suits you and there is nothing to buy. That is a real outcome and worth checking before spending anything — the desk height guide has the measurement.

What we'd buy

Find your height with books first. Then buy something that hits it.