Understanding PDF Page Sizes: A4, Letter, and More

# Understanding PDF Page Sizes: A4, Letter, and More

A comprehensive guide to PDF page sizes including A4, A3, Letter, and Legal. Learn when to use each size and how to convert between them.

Common PDF Page Sizes Explained

When working with PDFs, understanding page sizes is crucial for proper printing and document formatting.

International Paper Sizes (ISO 216)

The A-series is the international standard: • A4 (210 × 297 mm) - Most common worldwide • A3 (297 × 420 mm) - Twice the size of A4 • A5 (148 × 210 mm) - Half the size of A4

North American Sizes

• Letter (8.5 × 11 in / 216 × 279 mm) - US standard • Legal (8.5 × 14 in / 216 × 356 mm) - Legal documents • Tabloid (11 × 17 in) - Large format

When to Use Each Size

A4 - The Universal Choice

A4 is the standard for business documents, academic papers, and most printed materials outside North America.

Letter - For US Documents

If you're in the United States or sharing with US recipients, Letter size is often expected.

A3 - For Presentations

A3 is perfect for posters, architectural drawings, and documents that need more space.

Converting Between Sizes

When you need to standardize documents from different sources, use AltaPDF's auto-scaling feature: • Upload your mixed-size PDFs • Select your target size • Merge and download All pages will be proportionally scaled to fit your chosen size.

Conclusion

Understanding page sizes helps you create professional documents. With AltaPDF's scaling feature, you can easily standardize any PDF to your preferred size.

Ready to Try AltaPDF?

Merge your PDFs with automatic page scaling. 100% free, no uploads, completely private. Start Merging PDFs