Last updated: March 2, 2026 by Dr. David Park

Standard Paper Size Dimensions

Formula

Pixel dimensions = (paper mm / 25.4) × DPI

Paper sizes vary between the ISO standard (A series, used globally) and North American sizes (Letter, Legal, Tabloid). This converter shows dimensions in millimeters, inches, and pixels at your chosen DPI.

The ISO A series is based on an aspect ratio of 1:√2, where each size is half the area of the next larger size. A4 (210×297 mm) is the most common worldwide.

Common use cases:

  • Setting up print documents in design software
  • Calculating pixel dimensions for digital templates
  • Comparing paper sizes across ISO and US standards

Frequently Asked Questions

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Dr. David Park

Applied Mathematician, PhD Mathematics

David holds a PhD in Applied Mathematics from MIT. He has published research on numerical methods and computational algorithms used in engineering and scientific calculators.

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