PPI Calculator

PPI (Pixels Per Inch) is a measurement of pixel density that indicates how many pixels are packed into one inch of a display screen. The higher the PPI value, the sharper and more detailed images and text appear on your screen. Our PPI calculator helps you instantly determine the pixel density of any display by using the screen resolution and diagonal size.

Understanding PPI is essential when comparing monitors, smartphones, tablets, and televisions. A 1920×1080 resolution looks incredibly sharp on a 5-inch smartphone but appears less detailed on a 27-inch monitor because the same number of pixels are spread across a larger area, resulting in lower pixel density.

The PPI formula uses the Pythagorean theorem to calculate the diagonal pixel count, then divides by the physical diagonal size in inches. Here's the step-by-step process:

Step 1: Calculate Diagonal Pixels

First, find the diagonal resolution using the width and height in pixels: Diagonal Pixels = √(Width² + Height²). For a 1920×1080 display: √(1920² + 1080²) = √(3,686,400 + 1,166,400) = √4,852,800 = 2203 pixels.

Step 2: Calculate PPI

Divide the diagonal pixels by the diagonal screen size in inches: PPI = Diagonal Pixels ÷ Diagonal Inches. For a 24-inch Full HD monitor: 2203 ÷ 24 = 91.8 PPI. The same resolution on a 15.6-inch laptop gives: 2203 ÷ 15.6 = 141 PPI.

Understanding Dot Pitch

Dot pitch is the inverse of PPI, representing the distance between pixel centers in millimeters. It's calculated as: Dot Pitch = 25.4 ÷ PPI. A display with 100 PPI has a dot pitch of 0.254mm. Lower dot pitch values indicate higher pixel density and sharper images.

The ideal pixel density varies based on the device type and typical viewing distance. Here's what to expect from different displays:

Smartphones and Tablets

Modern smartphones typically range from 300 to 500+ PPI. Apple's Retina displays target approximately 326 PPI for iPhones, while flagship Android devices often exceed 400 PPI. At these densities, individual pixels become invisible to the naked eye at normal viewing distances (10-12 inches), creating razor-sharp text and images.

Laptops and Desktop Monitors

Laptop displays generally range from 100 to 250 PPI. Standard 15.6-inch Full HD laptops offer around 141 PPI, while 4K laptops can reach 280+ PPI. Desktop monitors typically have lower PPI (80-160) due to larger screen sizes, but this is acceptable given the greater viewing distance of 20-30 inches.

Televisions

TVs have the lowest PPI values, often between 40 and 80 PPI, even for 4K models. A 55-inch 4K TV has approximately 80 PPI. This lower density is sufficient because televisions are viewed from several feet away, where pixels aren't individually discernible.

While PPI and DPI (Dots Per Inch) are often used interchangeably, they technically measure different things. PPI refers to screen pixel density, while DPI refers to print resolution or the number of ink dots a printer places per inch.

In the context of digital displays, PPI is the accurate term. However, when preparing images for printing, DPI becomes relevant. A photo at 300 DPI contains 300 dots of ink per inch when printed. For high-quality prints, 300 DPI is the standard, while professional photography may require 600 DPI or higher.

Additionally, DPI is used in computing to describe mouse sensitivity, indicating how many screen pixels the cursor moves for each inch of physical mouse movement. Gaming mice often advertise DPI values ranging from 400 to 16,000+ DPI for precise control.

Higher pixel density directly translates to better visual quality. When comparing displays, PPI helps you understand whether a screen will look sharp or pixelated at your typical viewing distance.

Text Clarity and Readability

For work involving extensive reading or coding, higher PPI makes text appear smoother with cleaner edges. Displays above 150 PPI significantly improve text readability, reducing eye strain during prolonged use. This is why many professionals prefer high-resolution displays for productivity tasks.

Photo and Video Editing

Content creators benefit from high-PPI displays because they can see finer details in their work. A photographer editing on a 4K 27-inch monitor (163 PPI) can evaluate sharpness more accurately than on a 1080p monitor of the same size (82 PPI), ensuring exports look crisp across all devices.

Gaming Experience

While gamers often prioritize refresh rate over resolution, pixel density still impacts immersion. Higher PPI allows players to spot distant enemies more easily and appreciate detailed textures. However, demanding resolutions like 4K require powerful graphics cards to maintain smooth frame rates.