PPI Calculator
Calculate the pixel density (Pixels Per Inch) of your display. Essential for determining image sharpness and interface scaling.
For accurate PPI results, ensure your display is set to its native (recommended) resolution.
Visual Preview
Scaled representation of your resolution
How to use this tool
- Enter your display's Width and Height in pixels.
- Enter the Diagonal size in inches.
- Use Auto Detect to quickly grab your current resolution.
- Look at the Quality Rating to see how your display compares.
What is PPI?
PPI (Pixels Per Inch) is a measure of pixel density. It tells you how many pixels are packed into one inch of a screen. The higher the PPI, the more detail the screen can display and the sharper images will appear.
A standard 24-inch 1080p monitor has a density of roughly 92 PPI, while a 27-inch 4K monitor has a much higher density of 163 PPI.
The Formula
PPI = √(Width² + Height²) / Diagonal Size
Why Pixel Density Matters
Retina Resolution
When PPI is high enough, the human eye can't distinguish individual pixels at normal viewing distances. This is what Apple calls a "Retina" display.
UI Scaling
Higher PPI requires operating systems to "scale" the interface. Without scaling, icons and text on a 4K 27" monitor would be too small to read.
Print vs Digital
While screens use PPI, printers use DPI (Dots Per Inch). Generally, 300 DPI is the standard for high-quality professional printing.
Common PPI Benchmarks
| Device Type | Typical Size | Typical PPI |
|---|---|---|
| 1080p Monitor | 24 inch | 92 PPI |
| 1440p Monitor | 27 inch | 109 PPI |
| 4K Monitor | 27 inch | 163 PPI |
| MacBook Pro 14" | 14.2 inch | 254 PPI |
| iPhone 15 Pro | 6.1 inch | 460 PPI |
Frequently Asked Questions
Is a higher PPI always better?
Generally, yes, as it leads to a sharper image. However, extremely high PPI can put more strain on your GPU and may require aggressive UI scaling that some older applications don't handle well.
What is the difference between PPI and DPI?
PPI (Pixels Per Inch) refers to digital screens and the number of pixels they can display. DPI (Dots Per Inch) refers to physical printers and the number of ink dots they can place on a page. They are related but not identical.
How does viewing distance affect PPI?
The further away you are from a screen, the lower the PPI can be before you notice pixels. For example, a 60-inch 4K TV has a lower PPI than a phone, but because you sit much further away, it still looks sharp.
What is a 'Retina' display?
'Retina' is a marketing term used by Apple for displays with a pixel density high enough that the human eye cannot distinguish individual pixels at a typical viewing distance.
Does resolution alone determine sharpness?
No. Sharpness is determined by PPI, which is a combination of resolution and physical screen size. A 24-inch 1080p monitor is sharper than a 32-inch 1080p monitor because the pixels are packed more densely.