🔢 Pixel Density & Geometry

Display PPI & Pixel Density Calculator

Calculate exact Pixels Per Inch (PPI), sub-pixel pitch in millimeters, and optimal visual acuity viewing distance across any resolution and panel size.

Width (Pixels)

Height (Pixels)

Diagonal (Inches)

Pixel Density (PPI)108.79 PPIPixels Per Inch

Dot Pitch0.2335 mmPixel Size

Retina Distance31.6 inches (80 cm)20/20 Acuity Limit

Total Resolution3.69 MPTotal Screen Pixels

Mathematical Formula for Pixels Per Inch (PPI)

Pixels Per Inch is calculated using the Pythagorean theorem applied to the horizontal (W) and vertical (H) resolution divided by the diagonal screen size (D):

PPI = √( W² + H² ) / D

Visual acuity and pixel density optical diagram showing human eye retina threshold boundary curve — **Figure 8.1:** Retina visual acuity arc diagram illustrating human 20/20 vision angular resolution and threshold distance formulas.

Dot Pitch & Visual Acuity Distance

The dot pitch (distance between neighboring sub-pixel centers in millimeters) is:

Dot Pitch = 25.4 / PPI (mm)

The Retina Distance represents the minimum viewing distance where individual pixels become indistinguishable to a person with standard 20/20 visual acuity (1 arcminute resolving power):

Retina Distance = 3438 / PPI (inches)

Display SuiteResolution

What Is My Screen Size

Instant diagnostic reading screen resolution and device pixel ratio.

Display SuitePrecision

Middle of Monitor Finder

Calculate exact center coordinates with sub-pixel crosshair alignment.

Display SuiteDisplay Sync

Refresh Rate (Hz) Tester

Sub-frame monitor refresh rate test to verify native panel frequency.

Hardware Knowledge Base

Frequently Asked Questions

Technical answers to common hardware, refresh rate, and browser diagnostic questions.

What is a good PPI for gaming and text clarity?

A PPI of 108–110 (e.g. 27-inch 1440p) is considered the sweet spot for desktop gaming without requiring OS UI scaling. A PPI of 140–163 (e.g. 27-inch 4K or 32-inch 4K) provides ultra-crisp, print-quality text rendering.

What is the Retina Viewing Distance?

Retina viewing distance (calculated as 3438 / PPI in inches) is the threshold distance at which a person with 20/20 vision can no longer distinguish individual pixels on a display.