Paper Sizes in Australia: A4 Is Standard, Letter Exists in Niche Uses

The Short Answer

A4 (210 × 297 mm) is the universal standard paper size in Australia for virtually all business, government, educational, and personal printing. It is the default in every office, school, and home printer tray.

Where Letter Size (8.5 × 11 in / 215.9 × 279.4 mm) Appears

Letter size is not standard but can be encountered in specific contexts:

• Organizations with heavy U.S. ties (U.S. subsidiaries, joint ventures, defense contractors).
• Legal firms handling U.S. discovery or filings.
• Imported forms, templates, or pre-printed stationery from North America.
• Some specialized publishing or design workflows targeting the U.S. market.

Practical Implications

• Printers and copiers sold in Australia default to A4; letter-size trays are an optional extra.
• Office supply retailers (Officeworks, Winc, etc.) stock A4 overwhelmingly; letter paper is a specialty order.
• Government and regulatory forms are exclusively A4.
• International correspondence: When emailing PDFs to U.S. recipients, Australians often set page size to Letter to avoid formatting shifts, but domestic documents remain A4.

Why the Difference?

Australia adopted the ISO 216 (A-series) standard in the 1970s as part of metrication. The U.S. and Canada retained the legacy ANSI/Letter system. The two standards are close but not interchangeable—Letter is 6 mm wider and 18 mm shorter than A4—causing margins, pagination, and binding issues if mixed carelessly.

Bottom Line

If you're in Australia, buy A4. Keep Letter-size paper on hand only if you regularly exchange physical documents with North American partners who cannot accept A4.