Paper Size Converter
Standards Reference and Dimension Converter.
Quick Reference (mm)
| Size | Width | Height |
|---|---|---|
| A0 | 841 mm | 1189 mm |
| A1 | 594 mm | 841 mm |
| A2 | 420 mm | 594 mm |
| A3 | 297 mm | 420 mm |
| A4 | 210 mm | 297 mm |
| A5 | 148 mm | 210 mm |
| A6 | 105 mm | 148 mm |
| B0 | 1000 mm | 1414 mm |
| B1 | 707 mm | 1000 mm |
| B2 | 500 mm | 707 mm |
Paper Standards
Paper sizes are standardized globally by ISO 216 (the A and B series), except in North America which uses a different system (Letter, Legal).
Standards Explanations
ISO A Series
Based on ratio √2 (approx 1.414). A0 is 1m². Cutting it in half yields A1, then A2, etc. The standard for standard office paper worldwide (A4).
North American
Based on imperial inch measurements. Letter (8.5 x 11 in) is the standard for business and academic documents in the US and Canada.
Digital Resolutions
To print correctly, resolution matters. 300 DPI (dots per inch) is standard for print quality, while 72 or 96 DPI is standard for screens.
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From Paper to Pixels
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Whether you're creating a flyer, preparing a book cover, or setting up an InDesign document, getting the dimensions right from the start saves hours of frustration later.
ISO A-Series (Worldwide)
The international standard based on a constant 1:√2 aspect ratio. Each size is exactly half the previous.
North American Sizes
Used primarily in the US, Canada, and Mexico. Based on inches rather than metric.
DPI: Resolution for Print
DPI (Dots Per Inch) determines how crisp your print will be. Choose based on your use case:
Social media, websites, email graphics.
CSS pixels, Microsoft Office default.
Magazines, brochures, business cards.
Museum prints, detailed illustrations.
🖨️ The Golden Rule of Print
Pixels = Inches × DPI. To print an A4 document at 300 DPI: 8.27 × 300 = 2481 px wide, 11.69 × 300 = 3508 px tall.
Always add 3-5mm bleed if your design extends to the paper edge. This ensures no white borders appear after trimming.
Frequently Asked Questions
What is the A4 paper size in pixels?
The pixel dimensions of A4 depend on your DPI (Dots Per Inch): At 72 DPI: 595 × 842 px (web/screen). At 96 DPI: 794 × 1123 px (Windows standard). At 300 DPI: 2480 × 3508 px (print quality). Always use 300 DPI for professional printing.
What is the difference between A4 and Letter size?
A4 (210 × 297 mm) is the ISO standard used worldwide. Letter (8.5 × 11 inches = 216 × 279 mm) is the North American standard. A4 is slightly narrower and taller. Documents designed for one may not print correctly on the other without adjustment.
What does DPI mean?
DPI (Dots Per Inch) measures print resolution—how many dots of ink or pixels fit per inch. Higher DPI = higher quality. 72 DPI is for screens. 150 DPI is draft printing. 300 DPI is the standard for high-quality prints. 600+ DPI is for fine art reproduction.
How do I convert inches to pixels?
Use the formula: Pixels = Inches × DPI. For example, Letter size (8.5 × 11 inches) at 300 DPI = 8.5 × 300 = 2550 px wide and 11 × 300 = 3300 px tall.
What is the ISO A-series paper standard?
The ISO 216 standard defines A-series sizes where each size is half the area of the previous. A0 (841 × 1189 mm) is the largest. A1 = A0 ÷ 2, A2 = A1 ÷ 2, etc. The aspect ratio (1:√2 ≈ 1:1.414) is maintained, so scaling between sizes works perfectly.
What paper size should I use for posters?
Common poster sizes: A3 (297 × 420 mm) for small posters. A2 (420 × 594 mm) for medium posters. A1 (594 × 841 mm) for large posters. A0 (841 × 1189 mm) for very large displays. For US sizes, consider 11×17 (Tabloid), 18×24, or 24×36 inches.
What is Legal paper size?
Legal paper is 8.5 × 14 inches (216 × 356 mm). It's 3 inches taller than Letter size and is commonly used for legal documents, contracts, and forms in the United States. It's rarely used outside North America.
What is the B-series paper?
The B-series (ISO 216) sizes fall between A-series sizes. B0 is larger than A0/A1. B1 is between A0 and A1. This is useful when A-series doesn't quite fit. B-series is common for books, posters, and passports. B5 (176 × 250 mm) is popular for books in Asia.
What resolution do I need for printing photos?
For high-quality photo prints: 300 DPI minimum. For large format (viewed from distance): 150 DPI may suffice. For billboards: even 72 DPI works because they're viewed from far away. Always match your file's pixel dimensions to your print size × DPI.
Why does my document print with margins cut off?
Most printers have a non-printable area (3-5mm on each edge). Additionally, if you designed for A4 but printed on Letter (or vice versa), the content may shift or crop. Always check your document's page size matches your printer's paper settings.