IN/PX
InchPixels.com
Foundational Resolution Guide

How Many Pixels in an Inch? The DPI/PPI Relationship

Understanding the physical and digital relationship between imperial inches and digital pixel resolution.

W3C CSS Web Standard1 in = 96 px
Commercial Print Standard1 in = 300 px
Draft Newsprint Baseline1 in = 150 px
Legacy Display Baseline1 in = 72 px
Interactive Live CalculatorPre-calibrated for DPI vs. PPI Explained
DPI / PPI:
DPI
Bi-Directional Length Converter2.54 cm / 25.4 mm
IN
PX
Calculation Math Breakdown:
1 in × 96 DPI = 96 px
Reverse: 96 px ÷ 96 DPI = 1 in
Display Precision:
Aspect Ratio Preview1D Vector
1" ➔ 96px @ 96 DPI
Equivalent to 2.54 cm or 25.4 mm
Instant Developer ExportOne-click copy
Designer & Printmaker Preset Trays:

Overview & Resolution Specifications

A digital pixel has no fixed physical size—it is simply an electronic point of color data. An inch, however, is a fixed imperial physical length equal to 2.54 centimeters. The bridge connecting them is density resolution, measured as DPI (Dots Per Inch) or PPI (Pixels Per Inch). In modern CSS web specifications, 1 inch equals exactly 96 pixels. In commercial offset printing, 1 inch equals 300 pixels.

Resolution Breakdown Across DPI Standards

StandardDPIPixel DimensionsMegapixelsCommon Use Case
Legacy Apple Monitor72 DPI72 px per inchN/A1984 Macintosh display baseline
W3C CSS Standard96 DPI96 px per inchN/AModern browser layout engine
Draft Newspaper150 DPI150 px per inchN/ANewsprint and paperback books
Commercial Offset300 DPI300 px per inchN/AMagazines, photos, brochures
Archival Giclée600 DPI600 px per inchN/AMuseum-grade photographic prints

Frequently Asked Questions

Why does CSS define 1 inch as 96 pixels?
The W3C anchored the CSS reference pixel to an angular measurement (1/96th of an inch at typical arm-length viewing distance). This provides visual consistency across desktop monitors.
What is the difference between DPI and PPI?
PPI (Pixels Per Inch) measures digital display and sensor density. DPI (Dots Per Inch) measures physical ink droplets on paper. Both use the identical mathematical equation.