Paper Size Reference
Look up dimensions for any standard paper size in millimeters, centimeters, or inches. Covers ISO A-series and B-series (international), US Letter, Legal, Tabloid, and other North American sizes.
Paper sizes follow different standards internationally. Most of the world uses the ISO 216 standard (A-series), while the US and Canada primarily use Letter and Legal sizes.
ISO A-Series (International):
The A-series is based on two principles:
- All sizes have an aspect ratio of 1:√2 (≈1:1.4142)
- A0 has an area of exactly 1 square meter
Each subsequent size is half the previous one: A1 = A0 folded in half, A2 = A1 folded in half, etc.
Most Common Sizes:
- A4 (210 × 297 mm): Standard international paper, similar to US Letter
- US Letter (8.5 × 11 in / 215.9 × 279.4 mm): Standard in US/Canada
- A3 (297 × 420 mm): Double A4, used for larger documents
- US Legal (8.5 × 14 in): Used for legal documents in the US
- Tabloid/Ledger (11 × 17 in): Double Letter size
A4 vs. US Letter:
A4 is narrower but taller than US Letter. A4: 210 × 297 mm. Letter: 215.9 × 279.4 mm. This can cause formatting issues when printing documents designed for one size on the other.