21.5-Inch Monitor Dimensions and Where One Fits

21.5-inch monitor dimensions in inches, cm and mm

The figures below are the visible screen, calculated from the diagonal for a 16:9 panel. The second column covers the 21.45-inch panels that several brands use for the same size class; the difference is under 0.1 in.

Why 21.5-inch monitors are sold as 22-inch

Brands group monitors into size classes and round up. A model named "22-inch" or with "22" in its model number (Dell P2225H, LG 22MR410) uses a 21.45 or 21.5-inch panel. True 22.0-inch 16:9 monitor panels are rare, so assume any "22-inch" monitor is this size unless the spec sheet says otherwise. If you are buying a privacy filter or anti-glare film, order the 21.5-inch 16:9 size, not 22-inch, which is often cut for the old 22-inch 16:10 (1680 × 1050) monitors and is taller.

Overall size with frame and stand

The Dell P2225H, a current office model with a height-adjustable stand, shows the full footprint:

The frame adds only 0.25 in on each side, so a 21.5-inch monitor needs a space just under 20 in (50 cm) wide. Simpler tilt-only stands sit lower and have a fixed height, which helps under a low shelf but can put the screen too low for a tall user.

Where a 21.5-inch monitor makes sense

• Shallow or narrow desks. At normal working distance the whole screen is visible from as close as 20 in (50 cm), the near end of OSHA's 20 to 40 in recommended range. A desk 20 in (50 cm) deep is workable.
• Reception counters, kitchens and workshop benches. Spaces where a monitor sits in a cubby or on a shelf less than 20 in wide.
• Second screen next to a laptop. The screen is 10.5 in tall against about 7.6 in for a 15.6-inch laptop, so the two look reasonably matched side by side, and the pair needs about 34 to 35 in of width.
• Portrait screen for documents or chat. Rotated, the screen is 10.5 in wide and 18.7 in tall, and the frame is a little over 11 in wide. That fits beside a main monitor on most desks.
• Lightweight wall or arm mounting. At under 6 lb (2.6 kg) for the panel, it suits light-duty arms and slim wall brackets.

Resolution and sharpness

Almost every 21.5-inch monitor is 1920 × 1080. On this size that works out to 102 pixels per inch, noticeably sharper than the same resolution on a 23.8-inch screen (93 PPI) or a 27-inch screen (82 PPI). Text is about 10% smaller than on a 24-inch 1080p monitor at the same scaling, which most people read comfortably at 20 to 28 in (50 to 70 cm).

A person with 20/20 vision stops seeing individual pixels beyond about 34 in (85 cm) from a 21.5-inch 1080p screen. At the usual 24 in (60 cm) the pixel structure is faintly visible on small text but not distracting for office work.

21.5-inch vs 24-inch monitor and laptop screens

23.8-inch monitor 20.7 × 11.7 in21.5-inch monitor 18.7 × 10.5 in15.6-inch laptop 13.6 × 7.6 in

A 24-inch class monitor is 2 in wider and 1.2 in taller, with 22% more screen area. Choose the 21.5-inch when the space is the limit; otherwise the 24-inch monitor is the more versatile size. For laptop screen sizes, see the laptop dimensions guide, and for every monitor size the monitor size chart.

Mounting a 21.5-inch monitor

Mounting holes are either VESA 75 × 75 mm (common on budget and older 21.5-inch models) or 100 × 100 mm. Many arms and wall brackets include plates for both. Measure between hole centers on the back of the monitor before buying.

• Arm capacity: check the arm's minimum load as well as its maximum. A 2.6 kg panel is below the minimum of some heavy-duty gas-spring arms, which then will not hold position.
• No holes: some ultra-slim consumer models have no VESA mount. Clamp-style adapters exist but are less secure.
• Wall mounting: because the panel is light and only 2 in (5 cm) deep, a fixed or tilting bracket rated for small screens is enough. Set the top of the screen at standing or seated eye level, depending on how it will be used.

Desk sizes that suit compact setups are in the desk dimensions guide.

Frequently asked questions