A paper size converter lets you instantly look up and compare dimensions across international paper standards — ISO A and B series, US/North American formats like Letter and Legal, and common photo print sizes. Whether you are designing a brochure, preparing files for an overseas printer, or checking pixel dimensions for a specific DPI, this tool shows every measurement you need.
Paper Size Lookup
With Bleed (+3mm / +0.125" per side)
Visual Size Comparison
Complete Paper Size Reference
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How to Use the Paper Size Converter
Whether you are a graphic designer preparing files for international printing, a student formatting a document, or a photographer ordering prints, understanding paper sizes across different standards is essential. This free paper size converter shows every dimension you need — millimeters, centimeters, inches, and pixels at any DPI — for ISO, US, and photo paper formats.
Step 1: Select a Paper Size
Choose from the grouped dropdown menu. Sizes are organized into four categories: ISO A series (A0 through A7), ISO B series (B0 through B5), US/North American formats (Letter, Legal, Tabloid, Executive, Half Letter), and common photo print sizes (4x6 through 16x20). If your size is not listed, select "Custom size" and enter your own dimensions.
Step 2: Choose Your DPI
Select the DPI (dots per inch) for pixel calculations. Use 72 DPI for screen display, 150 DPI for draft prints, 300 DPI for standard professional printing, and 600 DPI for high-quality or fine-art output. The pixel dimensions update instantly when you change the DPI setting.
Step 3: Add Bleed If Needed
Toggle "Include bleed margin" to add 3mm (0.125 inches) to each side of the paper size. Bleed is the extra printable area that extends beyond the final trim edge, ensuring no white borders appear after cutting. This is standard for business cards, brochures, posters, and any commercially printed materials.
Step 4: Read the Dimensions
The results show your selected paper size in four unit systems: millimeters, centimeters, inches, and pixels. You also see the aspect ratio and total area in both square centimeters and square inches. The visual comparison section shows scaled rectangles so you can see how your selected size compares to other common formats at a glance.
Understanding ISO vs US Paper Sizes
The ISO A series is used worldwide and is based on a 1:1.414 aspect ratio, where each size is exactly half the area of the next larger size. US paper sizes (Letter, Legal, Tabloid) are used primarily in the United States and Canada. The most common comparison is A4 versus US Letter: A4 is slightly narrower and taller at 210 x 297 mm, while Letter is wider and shorter at 215.9 x 279.4 mm. Always confirm which standard your printer expects before submitting files.
Frequently Asked Questions
Is this paper size converter free?
Yes, this paper size converter is completely free with no limits or signup. All conversions run in your browser, so your data stays private and the tool works even offline once loaded.
Is my data safe when using this tool?
Absolutely. Everything runs locally in your browser. No data is sent to any server, there are no cookies tracking your usage, and no account is required. You can use this tool offline once the page has loaded.
What is the difference between A4 and US Letter paper?
A4 is 210 x 297 mm (8.27 x 11.69 inches) and is the international standard used in most countries. US Letter is 8.5 x 11 inches (215.9 x 279.4 mm), slightly wider and shorter. A4 has an aspect ratio of 1:1.414 while Letter is 1:1.294.
What DPI should I use for printing?
For standard document printing, 300 DPI is the most common choice and produces sharp, professional-quality output. Use 150 DPI for draft prints, 72 DPI for screen-only display, and 600 DPI for fine art or high-detail printing where maximum clarity is needed.
How does the ISO A paper size series work?
The ISO A series is based on a mathematical relationship where each size is half the area of the next larger size. A0 has an area of exactly 1 square meter. Each subsequent size (A1, A2, A3, A4, etc.) is created by halving the longer side. All sizes maintain the same 1:1.414 aspect ratio.
What is a bleed margin and when do I need one?
A bleed margin is extra space (typically 3mm or 0.125 inches) added beyond the trim edge of a printed piece. It ensures that colors and images extend to the very edge of the final cut piece without leaving white borders. You need bleed for any professionally printed item like business cards, brochures, or posters.
What paper size should I use for photos?
The most common photo print sizes are 4x6 inches (standard snapshots), 5x7 inches (portrait prints), 8x10 inches (wall display), 11x14 inches (large display), and 16x20 inches (poster size). For international photo printing, check the equivalent metric sizes using this converter.