How much space do you need for a dual monitor setup?

Two 24 inch monitors need a desk at least 47 or 48 inches (120 cm) wide, and they're comfortable on 59 or 60 inches (150 cm). Two 27s need 59 or 60 inches. That extra foot is the difference between a desk that just holds two screens and a setup where your mouse finally stops falling off the edge.

The catch is that a monitor's size is measured corner to corner, not across. Two 24 inch screens are about 42 inches wide side by side before you leave any gap, so the chart below adds up the monitors' real widths.

How big should a desk be for 2 monitors?

"Screens side by side" is the width of both monitors, frames included, with their edges touching. Screen size means the diagonal of a standard 16:9 widescreen monitor.

"Comfortable" is our rule of thumb, not a standard: about 8 to 12 inches of spare width for keyboard and mouse travel. Under about 5 inches, the setup feels tight.

The desk sizes are the US widths we sell: 47.2, 59.1, 70.9 and 78.7 inches in laminate, and 48, 60, 72 and 80 inches in timber and bamboo, hence "47 or 48". Our Dual Mini desks (32 x 20 in and 40 x 24 in) can't hold two 24 inch or larger monitors side by side.

Adding a laptop beside the screens

A 13 to 16 inch laptop is about 12 to 14 inches (30 to 36 cm) wide, and next to the monitors it needs its own patch of desk.

Put the laptop on a stand in front of the screens, or on an arm, and the first chart applies instead.

Quick size checks

Is a 40 inch desk big enough for two monitors? Not for two 24s. You will see 40 inches quoted for that pair, but the screens alone are about 42 inches across.

Is a 47 inch desk enough? For two 24s, yes, with about 5 inches to spare. For two 27s, no: they're about 48 inches across.

Is a 55 inch desk enough? Two 27s fit with about 7 inches spare. Two 32s, at about 56 inches, don't. Our nearest desk width is 59 or 60 inches.

Why the diagonal isn't the width

A 24 inch monitor is 24 inches corner to corner. Its width depends on its shape, and a standard desk monitor is 16:9 widescreen: 16 units wide for every 9 tall. For that shape:

Screen width = diagonal x 0.872

The 0.872 is 16 divided by the diagonal of a 16 by 9 rectangle (the square root of 337, about 18.36).

That's the screen alone. The bezel, the frame around it, adds a little. Published specs for three office monitors list real widths about 1 to 3 percent wider: about 21.2 inches (53.9 cm) for a 24 inch class model, 24.0 inches (61.1 cm) for a 27 inch and 28.1 inches (71.3 cm) for a 32 inch. The chart adds up those real widths.

To check your own pair, take the width from each spec sheet (usually listed under dimensions with stand), add any gap you want, then add 8 to 12 inches for keyboard and mouse room. The 0.872 shortcut works for 16:9 screens only, so for an ultrawide or any other shape, go straight to the spec sheet.

How deep should the desk be?

Width decides whether the screens fit. Depth decides how far back from them you sit. On the 27 and 32 inch examples above, the stand's foot takes about 7.5 to 9 inches (19 to 23 cm) of depth, straight out of the space between you and the screen.

OSHA's monitor guidance puts the screen at least 20 inches (50 cm) from your eyes. On a 29.5 inch deep desk with the stands pushed back, the screens sit about 20 to 22 inches from the front edge. With your eyes a little behind that, you clear the minimum, but not by much.

Our standard depth, 29.5 inches (75 cm) in laminate and 30 inches (76 cm) in timber and bamboo, is the one to choose when the monitors sit on their stands, especially 27s and 32s. A 24 inch (61 cm) deep desk works best with the screens on arms, which lift the stand foot off the desk.

When a dual monitor arm saves space (and when it doesn't)

An arm doesn't make a side by side pair any narrower. Two 27s in landscape are about 48 inches across on stands or on an arm. What an arm does change:

• Depth. The stand foot leaves the desk, giving back about 7.5 to 9 inches in front of you. That matters most on a 24 inch deep desk.
• Gap and angle. You can close the gap and angle both screens toward you without two stand feet in the way.
• Width, but only in portrait. Turned on its side, a monitor's width becomes its height. Two 27s in portrait span about 26.5 inches (67 cm) instead of 48, and two 32s about 31.4 inches (80 cm), before bezels. Portrait pays off for long documents or code.

Match the arm to the screens. The Desky Dual Monitor Arm takes two monitors 27 inches and under, 4.4 to 22 lb each, so it covers every row of the chart except 2 x 32. For a pair of 32s, the Desky Dual Slim Aluminium Monitor Arm takes 17 to 32 inch screens at 4.4 to 19.8 lb each, and its 180 degrees of rotation lets you turn a screen to portrait. Compare weight limits across our dual monitor arms, then see where to position your monitor arm.

Fitting two screens into a small space

Short on width? On a 47 or 48 inch desk, stick to two 24s. These three moves buy back more:

• Get the laptop off the side. On a stand in front of the screens or on an arm, it costs no width. See our desk setup with a laptop and monitor guide.
• Turn one screen to portrait. A 27 inch in landscape beside a 27 inch in portrait takes about 37 inches (93 cm) of screen width, not 47 (before bezels).
• Use a corner. OSHA notes that a corner, rather than a straight run of desk, can add space and depth for large monitors. See our L-shaped and corner desks.

Is it better to have two monitors or one big one?

A large single monitor appeals if you like one expansive picture. At Desky, we lean toward two. Gamers can play on one screen and keep guides or chat open on the other. At work, a video call or presentation sits on one screen while your work stays on the other.

One big screen does save width, though. Published specs put one 34 inch curved ultrawide at about 32 inches (81 cm) across, so a screen like that fits a 47 or 48 inch desk where two 27s, at about 48 inches, won't.

Once both are on the desk, our guide to sitting at a desk with two monitors covers height, distance and angle.

Getting both screens working

Extend, don't duplicate. Press the Windows key + P and choose Extend to spread one desktop across both screens. Duplicate mirrors one picture on both; PC screen only and Second screen only switch one off. In Display settings, the same choice is Extend these displays under Multiple displays.

Snap windows into place. Windows key + Left or Right arrow snaps a window to half the screen; Windows key + Z opens snap layouts.

A splitter won't extend. An HDMI splitter sends one picture to both screens: a mirror, not a second desktop. Each extended screen needs its own output from the computer, such as a second video port, a DisplayPort hub or daisy chain (MST), a USB display adapter or a dock. Our guide to monitor connections covers cables and ports.

A laptop as the second screen. A laptop's HDMI port is usually output only, so cabling two laptops together over HDMI won't show a picture. The supported Windows route is Projecting to this PC, using the optional Wireless Display feature. Mouse Without Borders, a Microsoft PowerToys tool, shares one keyboard, mouse and clipboard across up to four PCs, but each laptop keeps its own screen. More in our guide to setting up two laptops together.

Dual monitor setup: pros and cons

Pros

• More screen area for side by side work: two documents, a call beside your work, a game beside its guide.
• Layout options: both in landscape, one in portrait, or angled in an arc.

Cons

• More desk width and depth: two 27s need about 48 inches before keyboard room.
• Higher cost: a second monitor, and possibly an arm or a bigger desk.
• Setup time: cables, matching heights and lining up the screens.

Measure your desk, find your pair in the chart, and leave 8 to 12 inches for the keyboard and mouse. If the desk turns out to be the limit, our standing desks in 59 and 70.9 inch widths cover every pairing in the main chart.