Paper Size Converter
Compare and convert between ISO A/B/C series and North American paper sizes with dimensions in mm and inches
📐 Paper Size Standards
- • ISO A Series: International standard, each size is half the area of the previous
- • ISO B Series: Intermediate sizes between A series
- • ISO C Series: Envelope sizes designed to fit A series paper
- • US Sizes: Letter, Legal, and Tabloid are North American standards
- • Pixel Calculation: Pixels = (mm ÷ 25.4) × DPI
Continue Your Converters Journey
What is Paper Size Converter?
The Paper Size Converter shows dimensions for standard paper sizes in millimeters, inches, and points. It covers the ISO A-series (A0 through A10), US sizes (Letter, Legal, Tabloid, Ledger), and other common formats. You select a size and see its width and height in all three units. The tool also calculates aspect ratios and areas. All processing happens in the browser.
How does Paper Size Converter work?
This tool stores the exact dimensions for each standard paper size and converts them between mm, inches, and points. The ISO A-series uses a consistent aspect ratio of 1:root2, where each size is half the area of the previous one. US sizes use different dimensions based on inches.
Key Features
- Covers ISO A0 through A10
- US Letter, Legal, Tabloid, Ledger
- Dimensions in mm, inches, and points
- Aspect ratio and area calculations
- Side-by-side size comparison
- Copy dimensions to clipboard
- Runs in the browser with no uploads
- Reference chart for all sizes
Common Use Cases
Setting up print documents
Look up A4 dimensions in inches to set up a document in a US-based design application.
Comparing US and international paper sizes
Compare Letter (8.5 x 11 in) with A4 (210 x 297 mm) to understand layout differences.
Configuring printer settings
Find the exact mm dimensions for a paper size to enter into a custom printer setting.
Designing for international audiences
Check A3 dimensions for a poster that will be printed in Europe versus the US.
How to Use This Tool
Select a paper size
Choose from the dropdown of standard sizes.
View dimensions
The tool shows width and height in mm, inches, and points.
Compare sizes
Select a second size for side-by-side comparison.
Copy dimensions
Copy the values you need for your document setup.
Pro Tips
- 1
A4 is 210 x 297 mm (8.27 x 11.69 in). US Letter is 8.5 x 11 in (215.9 x 279.4 mm).
- 2
Each ISO A size is half the area of the previous: A5 is half of A4, A3 is double A4.
- 3
1 point = 0.3528 mm (PostScript point).
- 4
For print work, always confirm the paper size with your printer before designing.
Frequently Asked Questions
What paper sizes are included?
The tool covers the full ISO A-series (A0 through A10), US sizes (Letter, Legal, Tabloid, Ledger), and other common formats like Executive and Statement.
What is the difference between A4 and Letter?
A4 (210 x 297 mm) is slightly narrower and taller than US Letter (215.9 x 279.4 mm). A4 is the standard outside North America. Letter is the standard in the US and Canada.
Is my data sent to a server?
No. All conversion happens in your browser. Nothing is transmitted.
How does the ISO A-series work?
Each size in the A-series is half the area of the previous one. A0 is the largest (1 m squared area). A1 is half of A0, A2 is half of A1, and so on. The aspect ratio is always 1:root2.
Can I see dimensions in points for design software?
Yes. Each size shows width and height in millimeters, inches, and PostScript points.