A monitor arm lifts the screen off your desk and lets you move it. Whether one will work for you comes down to four checks: the mounting holes on the back of the screen, the weight, the way the arm attaches to your desk and where the screen ends up. This guide goes through them in that order. Gimaxo has not tested any arm, so we recommend no models and quote no prices. The figures come from documents that Humanscale, one arm maker, and VESA, the standards body, publish. They show what a maker states, nothing more.

Photo: Kyu3a, CC BY-SA 4.0, resized and converted (see Image credits). It shows one person’s desk with one arm, as an example of what an arm looks like in use. It does not show whether that mount suits its desk or is secure. We did not test or choose it.

This page used to be a monitor buying guide. It now covers arms and risers, and the monitor specification text is no longer here.

Arm or riser?

A riser raises the screen and nothing else. An arm lets you change height, distance and tilt, which matters because OSHA says a monitor’s support should let you modify viewing distance and tilt and rotation angles. If the only problem is that the screen sits too low, a riser may be enough. If you want to pull the screen closer or push it back, an arm is the tool that moves.

Check the back of the screen first

Arms attach to your monitor through a pattern of screw holes on the back, defined in a VESA standard called the Flat Display Mounting Interface (FDMI). VESA’s overview says the standard covers displays from 4 to 90 inches diagonal and splits them into size groups, each with its own mounting interface. Look for the holes on the back of your monitor, or in its manual or spec sheet.

Arms list the patterns they accept. Humanscale’s M2 Pro bracket, for instance, has 75 mm and 100 mm hole patterns in its assembly guide, and a Humanscale configurator page lists 100 by 100, 100 by 200 and 200 by 200 mm options. Measure the distance between your holes, center to center, and match it to the arm’s list. That tip is ours, not VESA’s.

If the holes sit deep in the back panel, the bracket may need to stand off the surface. Humanscale’s guide supplies longer screws and plastic spacers for that case. Check what your arm includes before you order.

Photo: Kyu3a, CC BY-SA 4.0, resized and converted (see Image credits). The plate on the back of this monitor is the part that matches the hole pattern. One person’s desk. The photo says nothing about whether the arm is rated for this screen or fixed safely. Not tested or chosen by Gimaxo.

Then the weight, and what it counts

Every arm states a weight range per screen. Look at both ends. Humanscale’s capacity table lists a lower limit as well as an upper one: 5 to 22 lb (2.3 to 10 kg) for its M2.1 and 6 to 28 lb (2.7 to 12.7 kg) for its M8.1. A footnote adds that 15 to 22 lb applies only to certain configurations. Its installation guide says the screen should move up and down easily and stay where you put it, and that an arm which rises or drops by itself is not balanced and needs adjusting.

Humanscale’s own documents give two different lower limits for one model, and we are not choosing between them. Its monitor arms product page lists the M2 Pro as “For Monitors: 5-22 lbs”. Its Pro Desk Mount Assembly Instructions, the document headed M2 Pro, give “M2 Pro: Weight Range: 6-22 lbs. (2.7-10 kg)”. Nothing we read says which applies to a particular unit or when the documents were written. Check the instructions that ship with your arm, or ask Humanscale for the figure for your exact model.

One thing the sources we read do not settle is whether a limit counts the stand. Neither Humanscale’s table nor VESA’s overview says so. Look in your monitor’s spec sheet for a weight listed without the stand, and in the arm’s manual for how it defines its limit. Our own reading is that a screen on an arm usually has its stand taken off, but your monitor’s manual is the one to confirm that.

VESA’s overview also gives weight ceilings for its size groups, for instance up to 14 kg for 12 to 22.9 inch displays and up to 22.7 kg for 23 to 30.9 inch ones. Those describe what the mounting interface covers. They are not the capacity of any arm.

Dual setups follow the same rule, per screen. Some systems also state a combined limit for the whole arm.

How it fixes to the desk

Humanscale’s guide describes three ways to attach its arm:

• Clamp. The clamp grips the edge of the desk. Two sets of screw holes cover a top up to 1.8 inches (48 mm) thick or up to 2.7 inches (68 mm) thick.
• Sliding mount. The base slides over the back edge until the clamp rests on it, then three screws are tightened.
• Bolt-through. You drill a 1/2 inch hole, or use an existing one up to 4 inches (102 mm) wide. A plate goes under the top. With a hole of 2 inches (51 mm) or more, cables can pass through.

Other makers’ limits will differ, so use your own arm’s numbers. The Humanscale guide gives a thickness and a hole size. It says nothing we could find about glass, hollow or thin tops. If your desk is one of those, follow your arm maker’s instructions or ask them, instead of assuming a standard clamp will do.

Reach and travel

An arm swings. Humanscale’s guide warns that its stop rings should be set so the screen cannot rotate past the edge of the desk. Leave clear space behind the desk for the arm to move, and check the range once the screen is on.

Set the screen once it is up

An arm gives you the adjustment. OSHA’s monitor page gives starting numbers:

• directly in front of you, no more than 35 degrees to the left or right;
• at least 20 inches (50 cm) away, with a preferred range of 20 to 40 inches (50 to 100 cm);
• the top of the screen at or slightly below eye level, and the center of the screen 15 to 20 degrees below horizontal eye level;
• tilted so it is perpendicular to your line of sight, usually by no more than 10 to 20 degrees.

The last two numbers are not the same angle. Tilt is how far you lean the screen back. The 15 to 20 degrees is how far below straight ahead your eyes look at the middle of the screen. HSE’s version is shorter: top of the screen level with your eyes, about an arm’s length away. Treat both as starting points and adjust to what feels right.

Cables

HSE’s workstation checklist says cables should be tidy and not a trip or snag hazard. A moving arm adds a rule of our own: leave enough slack for the whole range of travel, so nothing pulls when you swing the screen.

Before you order

• Find the VESA hole pattern on your screen and the patterns the arm lists.
• Check the weight limit, both ends, and how the maker counts it.
• Check the clamp or hole against your desk’s thickness and material.
• Plan the swing, with clear space behind the desk and slack in the cables.

For the order of decisions around the whole desk, see our gaming desk setup guide.

Image credits

Both photos in this guide are by Kyu3a and are licensed under the Creative Commons Attribution-ShareAlike 4.0 International license (CC BY-SA 4.0). License text: https://creativecommons.org/licenses/by-sa/4.0/. The license notice is the one given on each photo’s page on Wikimedia Commons, and the author asks for no other credit line.

• “Ultra-wide display with VESA arm - 1”, taken November 28, 2023. Source: https://commons.wikimedia.org/wiki/File:Ultra-wide_display_with_VESA_arm_-_1.jpg
• “Ultra-wide display with VESA arm - 2”, taken November 28, 2023. Source: https://commons.wikimedia.org/wiki/File:Ultra-wide_display_with_VESA_arm_-_2.jpg

Changes made by Gimaxo: each file was resized and converted to WebP, and the site shows it cropped to fit the page layout. Nothing else was altered apart from removing embedded metadata. These adapted files are shared here under the same license, CC BY-SA 4.0 (https://creativecommons.org/licenses/by-sa/4.0/), and anyone who reuses them must keep the credit above and the same license. The rest of this guide is not covered by that license. The creator does not endorse this guide. The brand name on the monitor belongs to its owner and is not licensed by this notice.

Sources

Named here as plain text. Pages read in November 2026.

• VESA, Flat Display Mounting Interface (FDMI) Overview
• Humanscale, M2 Pro Desk Mount Assembly Instructions
• Humanscale, Monitor Arms Weight Capacity (v20250501)
• Humanscale, monitor arms page and M2 Pro configurator
• OSHA eTool, Computer Workstations: Monitors
• HSE, Good posture when using DSE
• HSE, DSE workstation checklist (CK1)