Pixel density determines how crisp and sharp an image will appear on your display. PPI, which stands for Pixels Per Inch, is the measurement of pixel density. It is the number of pixels relative to the square inch surface. The more pixels and the smaller the screen size, the higher the PPI amount will be.
Using the following formula, we can calculate how dense a monitor’s pixel amount is in correlation to its monitor size.
Where:
- w = width of resolution (pixels)
- h = height of resolution (pixels)
- d = diagonal length of screen (inches)
The higher the pixel density, the more pixels there are on a screen, and the more detailed an image is. It will be sharper and more clear-looking.
That’s why nowadays you have technology pushing into 16K territory (move over 4K and 8K) for the best and sharpest image possible. That’s 16 times more pixels than 4K and 64 times more than 1080p!
These days you’ll also find monitors that are, for example, 27 inches big but only have a 1920 x 1080 resolution. Do the math, and you get a PPI of 82. That’s a terrible pixel density.
What’s the relationship between pixel density and resolution?
With an increase in monitor size, you should likewise see an increase in resolution. Otherwise, your image quality will suffer. Below you can see standard resolution and size combinations for monitors:
| Screen size (inches) | Monitor resolution | Aspect Ratio | PPI |
|---|---|---|---|
| 23.5″ | 1920 × 1080 | 16:9 | 94 |
| 24″ | 1920 × 1080 | 16:9 | 92 |
| 2560 × 1440 | 16:9 | 122 | |
| 27″ | 1920 × 1080 | 16:9 | 82 |
| 2560 × 1440 | 16:9 | 109 | |
| 3840 × 2160 (4K) | 16:9 | 163 | |
| 31.5″ | 1920 × 1080 | 16:9 | 70 |
| 2560 × 1440 | 16:9 | 93 | |
| 34″ | 2560 × 1440 | 16:9 | 86 |
| 3440 × 1440 | 43:18 | 110 | |
| 35″ | 2560 × 1080 | 21:9 | 79 |
| 49″ | 3840 × 2160 (4K) | 16:9 | 90 |
A monitor that measures 24 inches and has a resolution of 2560 x 1440 (1440p) hits the sweet spot and offers the best pixel density for the price. If you need to calculate PPI for different screen sizes and resolutions, then this convenient calculator can easily do the job for you.
What about ultrawide monitors?
Remember, bigger is not always better… that is unless everything’s bigger. The new trend of ultra-wide monitors can be exciting. That’s until you realize that they have a very low pixel density at their size and resolution. Couple that with their hefty price, and they become very unappealing.
Think about your graphics card
You should know that a higher resolution also means more work for your graphics card to render. The larger the resolution, the more pixel density, the better graphics card you’ll need to run your game. Keep this in mind when shopping for a new monitor or new graphics card. Technology is constantly pushing boundaries and, lately, we have seen releases of monitors with a 4K or a 3840 × 2160 (UHD) resolution.