US Paper Sizes - Complete Specification Guide
Complete guide to US paper sizes including Letter, Legal, Tabloid, and Executive. Physical dimensions and pixel conversions at common DPI settings.
Quick Reference - Common US Sizes
| Size | Inches | Millimeters | Pixels @ 300 DPI | Common Use |
|---|---|---|---|---|
| Letter | 8.5×11" | 216×279 mm | 2550×3300 px | Standard documents |
| Legal | 8.5×14" | 216×356 mm | 2550×4200 px | Legal documents |
| Tabloid | 11×17" | 279×432 mm | 3300×5100 px | Newspapers, posters |
| Executive | 7.25×10.5" | 184×267 mm | 2175×3150 px | Planners, stationery |
Standard US Paper Sizes
Letter (8.5×11")
Legal (8.5×14")
Tabloid / Ledger (11×17")
Executive (7.25×10.5")
Specialized US Paper Sizes
Half Letter (5.5×8.5")
Junior Legal (5×8")
Poster Sizes
Index Cards & Note Cards
Understanding DPI for Print
What is DPI?
DPI (Dots Per Inch) measures print resolution. It determines how many ink dots a printer places within one inch, directly affecting print quality and sharpness.
Common DPI Standards
- 72 DPI: Screen resolution (legacy standard). Used for web images and digital display. NOT suitable for print.
- 150 DPI: Acceptable for large format prints viewed from a distance (posters, banners). File sizes are manageable while maintaining reasonable quality.
- 300 DPI: Professional print standard. Required for documents, brochures, magazines, and any close-viewing print work. This is the industry standard.
- 600+ DPI: High-end commercial printing, especially for fine art and photography. Creates very large file sizes.
Choosing the Right DPI
For standard documents (Letter, Legal): Always use 300 DPI. This ensures crisp text and sharp images when printed.
For large posters (24×36" and above): 150 DPI is often sufficient, as viewers stand farther away. This also keeps file sizes manageable (a 24×36" poster at 300 DPI would be 7200×10800 px = 77.8 megapixels!).
For professional photography prints: Use 300 DPI minimum. For gallery-quality fine art prints, consider 360-600 DPI.
File Size Considerations
Higher DPI = larger files. A Letter-size document at 300 DPI (2550×3300 px) is over 8 megapixels. For full-color images with layers, this can easily exceed 50 MB per page.
Use appropriate compression (JPEG quality 80-90% for photos, PNG for graphics with transparency) to balance quality and file size.
US vs International Paper Sizes
Key Differences
US System: Based on inches, with arbitrary dimensions (8.5×11", 8.5×14", etc.). Sizes don't follow a mathematical relationship.
ISO 216 (A-Series): Based on √2 ratio (1:1.414). Each size is exactly half the previous one. A4 folded in half = A5. Used worldwide except US, Canada, and a few other countries.
Size Comparisons
| US Size | Closest ISO Size | Difference |
|---|---|---|
| Letter (8.5×11") | A4 (8.27×11.69") | Letter is wider, A4 is taller |
| Legal (8.5×14") | A4+ (no exact match) | Legal is significantly taller |
| Tabloid (11×17") | A3 (11.69×16.54") | Very similar, Tabloid slightly larger |
Why It Matters
If you're designing for international audiences, consider using A4 (210×297 mm) instead of Letter. If you must support both, design with safe margins that work for both sizes.
Safe area approach: Design within an 8×10.5" area, which fits comfortably on both Letter and A4 paper with margins.
Design Guidelines for US Paper
Margins & Bleeds
Standard margins: 0.5" on all sides for documents, 1" for formal letters. For bleeds, extend 0.125" (1/8") beyond trim size to prevent white edges.
Safe Zones
Keep important content (text, logos) at least 0.25" from edges. Printers may not print perfectly to the edge, and content could be cut off during trimming.
Color Modes
Use CMYK color mode for print, not RGB. RGB colors often appear different when printed. Convert and proof in CMYK before sending to print.
Typography for Print
Minimum readable font size: 8pt for body text, 6pt for fine print. Optimal reading size: 10-12pt. Use print-safe fonts (embed or outline fonts in PDFs).
Black Text
Use "rich black" (C:60 M:40 Y:40 K:100) for large black areas. Use pure black (K:100) for body text to avoid registration issues with small type.
File Formats
PDF is the gold standard for print. Use PDF/X-1a or PDF/X-4 for professional printing. TIFF works for images. Avoid Microsoft Office formats for commercial printing.