The PC Journal

MonitorsGuide

Monitor Size, Resolution and Pixel Density: Sharp Text at Your Distance

Sharpness comes from pixels per inch and how far you sit, not resolution alone. Work it out from the numbers on the spec sheet.

By The PC Journal7 min read

The short answer

Pixel density is the diagonal resolution in pixels divided by the diagonal size in inches. A 27-inch 1440p monitor is about 109 pixels per inch, a 27-inch 4K monitor is about 163, and a 32-inch 1080p-class panel falls near 69. Text looks cleaner as density rises, but a higher number only helps if you can sit close enough to see it and your operating system scales the interface sensibly.

How to calculate pixel density

Take the square root of width squared plus height squared, in pixels, and divide it by the diagonal in inches. A 2560 by 1440 panel has a diagonal of about 2,937 pixels, so at 27 inches the result is about 109 PPI, and at 32 inches it falls to about 92 PPI. A 3840 by 2160 panel has a diagonal of about 4,406 pixels, which gives about 163 PPI at 27 inches and about 138 PPI at 32 inches.

The same arithmetic explains why a large 1080p monitor looks soft. A 1920 by 1080 panel has a diagonal near 2,203 pixels, so 24 inches gives about 92 PPI and 27 inches only about 82 PPI. Each pixel is larger and easier to see, and curved diagonal strokes in text show stepping.

Because the calculation needs only the resolution and size, you can use it on any monitor, including ultrawide models. A 34-inch 3440 by 1440 panel is about 110 PPI, close to a 27-inch 1440p monitor, and a 49-inch 5120 by 1440 super-ultrawide is about 109 PPI.

Common sizes and approximate density

Calculated from the published resolution and diagonal. Real panels vary slightly with their exact active area.

Size and resolutionApprox. PPIWhat to expect for text
24-inch, 1920 x 108092Usable at arm's length; pixel structure visible up close
27-inch, 1920 x 108082Noticeably soft for text work
24-inch, 2560 x 1440122Crisp, small interface at 100% scaling
27-inch, 2560 x 1440109A common balance for games and office work
32-inch, 2560 x 144092Larger image at the cost of sharpness
32-inch, 3840 x 2160138Sharp text, comfortable at moderate scaling
27-inch, 3840 x 2160163Very sharp; needs scaling above 100%
34-inch, 3440 x 1440110Similar sharpness to 27-inch 1440p, wider view

Viewing distance and scaling

A higher pixel density only improves what you see when your eyes can resolve the individual pixels. Sit further back and a 92 PPI panel and a 163 PPI panel look more alike. Sit a typical desk distance away, usually somewhere between an arm's length and a little less, and the differences in text edges become easy to see, especially for small fonts.

Scaling turns extra pixels into smoother text instead of smaller text. On Windows, open Settings, System, Display and look at the Scale setting. On a 27-inch 4K monitor, 150 percent gives you an effective workspace of 2560 by 1440 with much sharper characters. On a 32-inch 4K monitor, 125 percent gives about 3072 by 1728 and 150 percent gives about 2560 by 1440.

Older applications may not scale well and can look blurred. If that applies to software you use daily, test your own applications on a monitor you can return before committing to a very high density.

Pick a size and resolution for your desk

  1. Measure your seated distance

    Sit as you normally do and measure from your eyes to where the screen will sit. If it is under about 60 cm, a 24 to 27-inch monitor is easier to take in without moving your head.

  2. Decide on the workspace you need

    Think in effective pixels after scaling. If you want the equivalent of 2560 by 1440 workspace with sharper text, a 27-inch 4K monitor at 150 percent does that.

  3. Check what the graphics card must drive

    A 4K image has 8,294,400 pixels, which is 2.25 times a 1440p image at 3,686,400. If you game at the native resolution, check that your graphics card suits it.

  4. Compare the calculated PPI

    Run the calculation for each candidate and compare the PPI. Two monitors at similar density will feel similar, whatever the box says about resolution.

Common mistakes

  • Choosing a 32-inch monitor at 1440p for text work.

    Instead: At about 92 PPI the text looks coarser. Consider 4K at 32 inches, or a 27-inch 1440p monitor.

  • Setting 4K at 100 percent scaling on a 27-inch monitor.

    Instead: Use 125 to 150 percent so that text is readable. Sharper text is the benefit of the extra pixels.

  • Judging sharpness by resolution alone.

    Instead: Compare the calculated pixels per inch for each candidate at its screen size.

  • Ignoring desk depth.

    Instead: A large monitor on a shallow desk makes edges hard to see. Measure first, and allow for any monitor arm.

Reading, coding and image work at different densities

People who read and write for hours care most about text edges. Higher density gives smoother curves in small fonts, which is why many writers and programmers prefer 4K at 27 or 32 inches with scaling, or 1440p at 27 inches as a lower-cost step.

Image and video work depends on whether you need to see detail at 100 percent. A 4K panel shows more of a photograph without zooming, while a 1080p panel shows less. If colour accuracy matters, density is secondary to the panel's colour coverage and calibration.

For games, density matters less than frame rate. A lower-density monitor can feel fine at normal gaming distance, and a higher-density one asks more of the graphics card. Think about what you do most hours of the day before choosing.

Next steps

  1. Best 27-inch 4K monitors
  2. Best 32-inch 4K monitors
  3. Best monitors for home office

Sources

  1. Microsoft SupportMicrosoft · Manufacturer documentation

This guide explains a decision process. It does not contain product rankings, benchmark results or hands-on measurements. How we research

Related guides