📄 List of paper sizes

List of A size, B size (JIS/ISO), and special paper sizes. mm/cm/inch switching, automatic pixel count calculation by DPI specification. Visual comparison chart included.

Visual Comparison

Usage and Application Examples

  • Check size when designing printed materials
  • Calculate the number of pixels with DPI specification (for web/print)
  • Comparison of A- and B-format sizes and confirmation of postcard and business card sizes
  • International sizes can be handled by switching between mm/cm/inch units

What is Paper Size Reference?

Paper Size Reference is a comprehensive tool that displays standard paper dimensions across multiple formatting systems. It covers ISO A-series (A0–A10), B-series, Japanese Shiroku-ban and Kesshaku-ban formats, plus specialty sizes like postcards, business cards, and envelopes. This tool eliminates guesswork when designing documents, preparing printing projects, or working internationally—especially valuable since paper standards vary significantly by region and industry.

How to Use

Simply open the Paper Size Reference tool and browse through categories of paper sizes. Each entry displays dimensions in both millimeters and inches, along with the aspect ratio. To use it for your project, identify which format system applies (ISO A-series for most international documents, Japanese B-series for domestic use), then note the exact dimensions. You can compare sizes side-by-side to understand scaling relationships—for instance, A4 folds to become A5. Copy the dimensions for your design software or provide them to your printer. The tool's organized layout makes it easy to distinguish between portrait and landscape orientations.

Use Cases

Graphic designers rely on this tool when creating documents for print, ensuring layouts match final output dimensions before sending to production. Architects and engineers use it to verify paper standards for technical drawings and blueprints. Small business owners preparing business cards, letterheads, or postcards can instantly confirm the correct dimensions without manual research. International teams collaborating on documents benefit from seeing how A-series sizes translate to practical measurements in inches. Marketing professionals planning direct mail campaigns can check envelope and postcard dimensions to ensure artwork fits and aligns properly.

Tips & Insights

Always account for printer margins and bleed areas when designing near the edges. Higher-resolution printing (300 DPI minimum) is standard for professional outputs—keep this in mind when exporting from design software. Understanding that A-series paper dimensions follow a 1:√2 aspect ratio helps predict how documents scale when folded or resized. Japanese B-series sizes differ from ISO B-series, so verify which standard applies in your region. For specialty sizes like Japanese postcards or business cards, bookmark dimensions to maintain consistency across projects.

Frequently Asked Questions

What is the size of A4 (mm x mm)?

A4 size is 210mm x 297mm. In inches it is approximately 8.27 x 11.69 inches or 595 x 842 pixels at 72 dpi.

What is the difference between Japanese B-format and ISO B-format?

Japanese B size (JIS B size) is one size larger than ISO B size. For example, JIS B5 is 182x257mm and ISO B5 is 176x250mm. JIS B is the standard size used in Japan.

What is the relationship between DPI and the number of pixels?

Pixels = (mm / 25.4) x DPI. For example, an A4 (210mm) print at 300 dpi will have a width of 2480 pixels. 72 dpi is common for the web and 300-350 dpi for printing.

What is the difference between Letter and A4 sizes?

Letter size (8.5" × 11" or 215.9 × 279.4 mm) is standard in North America, while A4 (210 × 297 mm) is used internationally. Letter is slightly wider and shorter than A4, making it unsuitable for A-format paper trays on most modern printers worldwide.

How do I calculate the pixel dimensions for different paper sizes at a specific DPI?

Multiply the paper dimensions in inches by your desired DPI. For example, A4 at 300 DPI is (8.27" × 11.69") × 300 = 2480 × 3508 pixels. This formula works for any paper size and DPI combination.

What are the most common paper sizes for business cards and postcards?

Business cards are typically 3.5" × 2" (89 × 51 mm), while postcards are usually 4" × 6" (101.6 × 152.4 mm) in North America or 100 × 148 mm internationally. These sizes are standardized to fit standard mailboxes and card holders.

Do A, B, and C series papers maintain the same aspect ratio?

Yes, all ISO paper series (A, B, and C) maintain a 1:√2 aspect ratio, which means when you fold a sheet in half, you get two smaller sheets with identical proportions. This makes scaling and folding operations predictable across all sizes.

What is the purpose of C-format paper sizes?

C-format sizes are designed specifically for envelopes that fit A-format letters. For example, C4 envelopes hold unfolded A4 paper, while C5 envelopes hold A4 paper folded in half. This system ensures mail compatibility across ISO standard formats.

How do I convert between metric and imperial paper measurements?

Multiply millimeters by 0.0394 to get inches, or multiply inches by 25.4 to get millimeters. Most design software allows you to work in either unit, and this tool displays both for easy reference and comparison.