Paper Sizes Reference

Complete reference for A-series, B-series, US, and photo paper sizes with dimensions in mm, cm, and inches

A paper size reference gives you the exact dimensions for every standard paper format used around the world. The ISO A-series (A0–A10) is used in most countries, while the US uses Letter, Legal, and Tabloid. Photo sizes (4×6, 5×7, 8×10) follow their own conventions. Toggle between mm, cm, and inches to see any size in your preferred units.

Visual Scale Comparison

Showing relative sizes to scale. Hover or tap a size card for details.

Paper Size Dimensions

Name Width Height

How to Use the Paper Sizes Reference

This free paper size reference lists every major standard paper format with exact dimensions in millimeters, centimeters, and inches. Use it to find the right paper size for printing, design, photography, or international document exchange.

Step 1: Choose Your Unit

Click mm, cm, or in to switch between millimeters, centimeters, and inches. All dimensions update instantly across the table and the visual scale diagram. Millimeters are the standard for ISO sizes; inches are preferred for US sizes and photo prints.

Step 2: Filter by Series

Use the category tabs to narrow down the list. A Series covers A0 through A10 — the international standard used in Europe, Asia, and most of the world. B Series covers B0 through B5, used for posters and book covers. US Sizes covers Letter, Legal, Tabloid, Ledger, Executive, and Half Letter. Photo Sizes covers 4×6, 5×7, 8×10, and 11×14 inch print formats.

Step 3: Search for a Specific Size

Type in the search box to filter by name (e.g., "A4", "Letter", "Legal"), dimensions (e.g., "210"), or use case (e.g., "envelope"). The table updates as you type. The visual scale diagram also updates to show only the matching sizes.

Understanding ISO A-Series Paper

The ISO A-series is based on a single rule: each size is half the area of the previous one, and the aspect ratio is always 1:√2 (≈1:1.414). This means an A4 sheet folded in half is exactly A5. A0 has an area of exactly 1 m². This elegant system makes scaling documents between sizes lossless — no margins or cropping needed when scaling A4 to A3 or A5.

US vs ISO Paper Sizes

The US uses its own paper size system. Letter (8.5×11 in) is the most common, used for business documents and home printing. Legal (8.5×14 in) is used for contracts and legal filings. Tabloid (11×17 in) is used for newspapers and oversized prints. These sizes do not follow the ISO geometric progression, which is why scaling between them often requires reformatting the document.

Photo Print Sizes

Photo sizes are defined by the printed image area, not the paper sheet. A 4×6 inch print is the most common — it matches the 2:3 aspect ratio of most digital cameras. A 5×7 inch print requires slight cropping of 2:3 photos. An 8×10 inch print has a 4:5 ratio, requiring more significant cropping. Always check the aspect ratio before ordering prints to avoid unexpected cropping.

Frequently Asked Questions

Is this paper sizes reference free?

Yes, completely free with no account required. All data is built into the page and works offline — nothing is sent to any server.

What is the size of A4 paper in inches?

A4 paper is 8.27 × 11.69 inches (210 × 297 mm). It is the most commonly used paper size worldwide outside North America, equivalent to the US Letter size but slightly narrower and taller.

What is the difference between A4 and US Letter?

US Letter is 8.5 × 11 inches (216 × 279 mm), while A4 is 8.27 × 11.69 inches (210 × 297 mm). Letter is slightly wider but shorter than A4. Letter is standard in the USA and Canada; A4 is standard in most other countries.

How are ISO A-series paper sizes calculated?

ISO A-series sizes follow a mathematical rule: each size is exactly half the area of the next larger size, and the aspect ratio is always 1:√2 (approximately 1:1.414). A0 has an area of exactly 1 square meter. A1 is half of A0, A2 is half of A1, and so on down to A10.

What is the largest standard paper size?

In the ISO A-series, A0 is the largest at 841 × 1189 mm (33.1 × 46.8 inches). In the B-series, B0 is even larger at 1000 × 1414 mm. For US sizes, ANSI E (Arch E) at 34 × 44 inches is one of the largest standard sheets used in engineering and architecture.

What paper size is used for passports and ID photos?

Passport photos vary by country. In the US, the standard passport photo is 2 × 2 inches (51 × 51 mm). EU countries typically use 35 × 45 mm. This reference tool covers standard photo print sizes like 4×6, 5×7, and 8×10 inches commonly used for prints.

What is Ledger vs Tabloid paper?

Ledger and Tabloid refer to the same sheet (17 × 11 inches / 432 × 279 mm), but in different orientations. Tabloid is portrait (11 × 17 inches) and Ledger is landscape (17 × 11 inches). Both are twice the size of US Letter.

What paper size should I use for printing photos?

The most popular photo print sizes are 4×6 inches (standard print), 5×7 inches (medium), and 8×10 inches (large). For professional portraits, 11×14 inches is common. Check your photo's aspect ratio against the print size to see if cropping will be needed.