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Paper Size Guide

Explore paper size standards from around the world and choose the most suitable specification for your documents

A Series Paper Sizes

The A series is the most widely used paper size standard internationally, based on ISO 216. Each size is half the area of the next larger size when folded along the longest side.

A0
A
The largest standard size in the A series, commonly used for technical drawings and large posters.
mm: 841 × 1189
inches: 33.11" × 46.81"
Common uses: Technical drawings
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A1
A
Half the size of A0, popular for flip charts and large format printing.
mm: 594 × 841
inches: 23.39" × 33.11"
Common uses: Flip charts
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A2
A
Commonly used for small posters, diagrams, and large tables.
mm: 420 × 594
inches: 16.54" × 23.39"
Common uses: Small posters
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A3
A
Popular for drawings, diagrams, and small posters. Double the size of A4.
mm: 297 × 420
inches: 11.69" × 16.54"
Common uses: Drawings
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A4
A
The most commonly used paper size worldwide. Standard for letters, documents, and magazines.
mm: 210 × 297
inches: 8.27" × 11.69"
Common uses: Letters
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A5
A
Half the size of A4, commonly used for notebooks, small flyers, and greeting cards.
mm: 148 × 210
inches: 5.83" × 8.27"
Common uses: Notebooks
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A6
A
Quarter the size of A4, perfect for postcards and small notebooks.
mm: 105 × 148
inches: 4.13" × 5.83"
Common uses: Postcards
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A7
A
Very small format perfect for business cards, index cards, and mini reference materials.
mm: 74 × 105
inches: 2.91" × 4.13"
Common uses: Business cards
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A8
A
Tiny format ideal for playing cards, small labels, and compact identification cards.
mm: 52 × 74
inches: 2.05" × 2.91"
Common uses: Playing cards
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A9
A
Extremely small format used for postage stamps, micro labels, and specialty printing.
mm: 37 × 52
inches: 1.46" × 2.05"
Common uses: Postage stamps
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A10
A
The smallest A series size, used for security tags, tiny labels, and specialized applications.
mm: 26 × 37
inches: 1.02" × 1.46"
Common uses: Security tags
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Understanding Paper Size Standards

The ISO 216 standard defines international paper sizes using a mathematical approach. The aspect ratio of all sizes in the A series is approximately 1:√2 (1:1.414), which means that folding a sheet in half along its longer side will result in two sheets with the same aspect ratio as the original.

This system is used worldwide except in the United States and Canada, where different standards like Letter (8.5" × 11") and Legal (8.5" × 14") are more common. The A4 size (210 × 297 mm) is the most widely used format globally for letters, documents, and printing.

Each paper size series serves specific purposes: A series for general documents, B series for books and posters, C series for envelopes, and specialized formats for business applications.

Precise Dimensions

Get exact measurements in millimeters, inches, and pixels for 72, 150, and 300 DPI. Perfect for design, printing, and layout work.

• Millimeter precision for international standards
• Inch measurements for US compatibility
• Pixel dimensions for digital design
• Multiple DPI options for different uses

Digital & Print Ready

Whether you're designing for web, print, or both, get the right dimensions for your project with our comprehensive size guide.

• 72 DPI for web and screen display
• 150 DPI for standard print quality
• 300 DPI for high-quality printing
• Aspect ratio calculations included

Professional Applications

Understand the common uses and applications for each paper size to choose the right format for your specific needs.

• Business documents and letters
• Marketing materials and brochures
• Academic papers and reports
• Books, magazines, and publications
✦ Features

Professional Paper Size Standards

Master the art of document presentation with comprehensive paper size knowledge that enhances your professional image.

International Standards

Complete coverage of ISO, ANSI, JIS, and other global paper size standards for professional documentation.

Regional Compatibility

Understand regional preferences and ensure your documents are properly formatted for any global audience.

Document Types

Optimal paper sizes for business letters, resumes, contracts, presentations, and personal correspondence.

Print Ready

Precise measurements in millimeters, inches, and pixels for both screen display and professional printing.

Layout Optimization

Guidelines for choosing the right paper size to enhance readability and professional appearance.

Best Practices

Industry-standard recommendations for different document types and professional applications.

✦ How It Works

Choose the Perfect Paper Size

Follow these simple steps to select the most appropriate paper size for your document needs.

1

Identify Document Type

Determine whether you're creating a business letter, resume, contract, presentation, or personal correspondence.

2

Consider Your Audience

Choose between international standards (A4) for global reach or regional preferences (Letter) for local audiences.

3

Select & Format

Use our size guide to get exact measurements and format your document with the chosen paper size specifications.

FAQ

Frequently Asked Questions

Common questions about paper sizes and document formatting standards.

What's the difference between A4 and Letter size?

A4 (210×297mm) is the international standard used worldwide, while Letter (8.5×11 inches) is primarily used in the United States. A4 is slightly narrower and taller than Letter size.

When should I use Legal size paper?

Legal size (8.5×14 inches) is typically used for legal documents, contracts, and official forms in the United States. It provides extra length for comprehensive documentation.

Are ISO paper sizes used globally?

Yes, ISO paper sizes (A, B, C series) are used in most countries worldwide except the United States, Canada, and parts of Mexico, which primarily use ANSI sizes.

What paper size should I use for resumes?

Use A4 for international applications or Letter size for US-based positions. Both are widely accepted, but matching regional preferences shows attention to detail.

How do I convert between different paper size standards?

Our guide provides exact measurements in millimeters, inches, and pixels for easy conversion between different standards and printing requirements.

What's the best paper size for business correspondence?

A4 is the global standard for business correspondence, while Letter size is preferred in North America. Choose based on your primary audience location.