Pixel Density (PPI) Calculator

Calculate the pixel density (pixels per inch) of display devices. Enter screen resolution and diagonal size to get accurate PPI values.

Enter Screen Parameters

Horizontal Pixels Number of pixels across the screen width

Vertical Pixels Number of pixels across the screen height

Diagonal Size (inches) Diagonal length of the screen in inches

Calculation Result

-- PPI

Pixels Per Inch

What is PPI (Pixel Density)?

PPI (Pixels Per Inch) is a unit that measures the pixel density of display devices. It represents how many pixel points are contained within one inch of length. The higher the PPI value, the finer the display effect, and the clearer and sharper images and text appear.

How is PPI Calculated?

The PPI calculation formula is: PPI = √(horizontal pixels² + vertical pixels²) / diagonal inches. First calculate the pixel diagonal length of the screen, then divide by the physical diagonal length to get the number of pixels per inch.

Why is PPI Important?

PPI has a direct impact on display quality. High PPI displays can present clearer text, finer image details, and reduce pixel graininess. For designers and developers, understanding the PPI of target devices helps optimize image resources and ensure optimal display effects on screens of different densities.

PPI Application Scenarios

Web Design: Prepare appropriate image resources for devices with different PPI
App Development: Ensure UI elements display correctly on various screens
Print Design: Understand the difference between screen display and print output
Device Selection: Compare display quality of different monitors

Typical PPI Values for Common Devices

Device	Resolution	Size	PPI
iPhone 15 Pro	2556×1179	6.1"	460
MacBook Pro 16"	3456×2234	16.2"	254
Dell UltraSharp 4K	3840×2160	27"	163
Samsung 4K TV	3840×2160	55"	80
iPad Pro 12.9"	2732×2048	12.9"	264

How to Use Our PPI Calculator?

Enter the horizontal pixel count of the screen (e.g., 1920)
Enter the vertical pixel count of the screen (e.g., 1080)
Enter the diagonal size of the screen (e.g., 15.6 inches)
The system will automatically calculate and display the PPI value

For example: A 15.6-inch 1920×1080 display has a PPI value of approximately 141.21, meaning each inch contains about 141 pixel points.

PPI vs DPI: What's the Difference?

PPI and DPI are often confused, but they have different application scenarios. PPI (Pixels Per Inch) is mainly used to describe the pixel density of digital display devices, while DPI (Dots Per Inch) is mainly used to describe the resolution of printing devices. In the context of web design and screen display, we typically use PPI to measure display quality.

Common PPI Value Reference

Low Density (72-120 PPI): Traditional monitors, large TVs
Medium Density (120-200 PPI): Standard laptops, desktop monitors
High Density (200-300 PPI): High-resolution laptops, tablets
Very High Density (300+ PPI): Smartphones, Retina displays

Frequently Asked Questions (FAQ)

What is a good PPI for a monitor?

For general use, 100-150 PPI is adequate. For professional work, 200+ PPI is recommended. Gaming typically works well with 100-200 PPI, while graphic design benefits from 200+ PPI for sharp detail work.

Does a higher PPI always mean better image quality?

Not necessarily. While higher PPI provides sharper images, other factors like color accuracy, contrast ratio, and panel technology also significantly impact overall image quality. Very high PPI can also strain system resources.

How does PPI affect gaming and video editing?

For gaming, moderate PPI (100-200) often provides the best balance of sharpness and performance. For video editing, higher PPI (200+ PPI) helps with precise editing and color grading, but requires more powerful hardware.

Can the human eye tell the difference between high PPI displays?

The human eye can typically distinguish up to about 300 PPI at normal viewing distances. Beyond this point, improvements become less noticeable unless viewing very close to the screen.