Screen DPI & PPI Calculator
Determine the exact sharpness and pixel density of monitors, laptops, and mobile screens. Calculate dot pitch and visual retina distance.
Dot Pitch: 0.156 mm center-to-center spacing between subpixels.
Understanding Pixel Density, Dot Pitch & Visual Acuity
PPI vs DPI vs Dot Pitch
PPI (Pixels Per Inch) measures electronic display density along the diagonal. DPI (Dots Per Inch) technically applies to printer ink droplets on paper. Dot Pitch measures the physical millimetric gap between adjacent subpixels (smaller dot pitch = crisper text rendering).
The Physics of "Retina" Viewing Distance
Under 20/20 vision, the human eye resolves approximately 1 arcminute (1/60th of a degree) of visual angle. At a normal desk distance of 20–28 inches, a monitor with ~160–220 PPI appears completely smooth without pixelation (forming the scientific basis of Apple's Retina standard).
OS UI Scaling & HiDPI Rendering
High PPI displays (such as 4K at 27") require 150% or 200% OS scaling in Windows and macOS. Running integer 200% (2×) scaling produces razor-sharp vector typography, while fractional scaling (like 125% or 175%) may introduce subtle subpixel font antialiasing artifacts.