📄Paper Size Calculator
Get exact dimensions for any paper size (A0–A6, Letter, Legal, Tabloid) in millimeters, inches, and pixels at any DPI resolution.
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Width
210
A4 portrait: 210 × 297 mm. In mm: 210 × 297mm. In inches: 8.27" × 11.69".
Paper Dimensions
210
297
8.268
11.693
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Paper Size Calculator: A4, Letter, Legal and Every Standard Dimension
A paper size calculator and paper size converter and chart belongs in every designer's and office worker's toolkit. Whether you need to know exact printer paper dimensions in millimeters, confirm the pixel count for a print-ready file, or understand why your US Letter document prints with white borders on a foreign printer, this reference covers all the standard sizes and the logic behind them.
A4 to US Letter Paper Size Comparison
The A4 to US Letter paper size comparison is the most common source of printing confusion for international document sharing. The two sizes look nearly identical at a glance but differ in both dimensions in ways that matter for layout.
- A4: 210 x 297 mm, or approximately 8.27 x 11.69 inches
- US Letter: 215.9 x 279.4 mm, or exactly 8.5 x 11 inches
Letter is 0.23 inches wider but 0.69 inches shorter than A4. A document with text or graphics close to the bottom margin on A4 will be clipped when printed on Letter. Conversely, a Letter-formatted document printed on A4 may lose content near the right edge. For documents shared internationally, setting margins of at least 1 inch on all sides and keeping content within a safe zone of 7.5 x 10.5 inches ensures the file prints acceptably on both sizes without reformatting.
A4 is the default paper size in over 150 countries and is produced under the ISO 216 standard. US Letter is the default in the United States, Canada, and parts of Mexico, and is specified by the ANSI standard. Most word processors and PDF applications allow you to set a document size independently of the printer's physical paper, so you can always specify which standard your document targets.
International Paper Size Chart A3 A4 A5
The ISO 216 A-series is built on a single elegant rule: every size has an aspect ratio of 1 to the square root of 2 (approximately 1:1.414). This means folding any sheet in half along its longer dimension produces the next smaller size with the same proportions. A3 folded once becomes A4. A4 folded once becomes A5. The largest standard size, A0, has an area of exactly one square meter.
International paper size chart showing portrait dimensions:
- A0: 841 x 1189 mm (33.1 x 46.8 inches) - used for large posters and technical drawings
- A1: 594 x 841 mm (23.4 x 33.1 inches) - large format posters
- A2: 420 x 594 mm (16.5 x 23.4 inches) - architectural drawings, display boards
- A3: 297 x 420 mm (11.7 x 16.5 inches) - spreads, brochures, tabloid equivalent
- A4: 210 x 297 mm (8.27 x 11.69 inches) - standard office and document printing
- A5: 148 x 210 mm (5.83 x 8.27 inches) - notebooks, flyers, half-fold A4
- A6: 105 x 148 mm (4.13 x 5.83 inches) - postcards, notepads
US paper sizes follow a different system with no consistent mathematical relationship between sizes. Letter (8.5 x 11 in), Legal (8.5 x 14 in), and Tabloid (11 x 17 in, also called Ledger in landscape orientation) are the three primary US office sizes. The Tabloid format serves a role roughly equivalent to A3 in European workflows.
Convert Paper Dimensions Between mm and Inches
To convert paper dimensions between mm and inches, divide millimeters by 25.4 (since 1 inch equals exactly 25.4 millimeters). To go the other direction, multiply inches by 25.4. A few useful conversions:
- A4 width: 210 mm divided by 25.4 = 8.268 inches
- A4 height: 297 mm divided by 25.4 = 11.693 inches
- US Letter width: 8.5 inches times 25.4 = 215.9 mm
- US Legal height: 14 inches times 25.4 = 355.6 mm
When converting paper sizes to pixels for digital files, the result depends on the resolution target measured in DPI (dots per inch for print) or PPI (pixels per inch for screens). The formula is: pixels = dimension in inches times DPI. An A4 sheet at 300 DPI for professional print output is 2,480 x 3,508 pixels in portrait orientation. The same sheet at 72 DPI for screen preview is 595 x 842 pixels, the standard PDF preview size used by Adobe Acrobat and most PDF viewers.
Portrait and Landscape Orientation
Portrait orientation means the shorter dimension is the width and the longer dimension is the height, like a standard letter or page in a book. Landscape orientation flips these, placing the longer dimension as the width. A4 in landscape is 297 mm wide by 210 mm tall. Tabloid and Ledger are technically the same sheet (11 x 17 inches), distinguished only by orientation: Tabloid is portrait, Ledger is landscape.
For presentations, widescreen slides, and spreadsheets with many columns, landscape is the natural choice. For body text, reports, and most documents, portrait is standard. Printers handle both orientations automatically when the correct paper size is specified in the print dialog.
Frequently Asked Questions
What is the difference between A4 and US Letter paper?
A4 measures 210 x 297 mm (8.27 x 11.69 inches) and is the international standard used in over 150 countries under ISO 216. US Letter measures 215.9 x 279.4 mm (8.5 x 11 inches) and is the default in the United States, Canada, and parts of Mexico. Letter is slightly wider (by 0.23 inches) but notably shorter (by 0.69 inches). Documents designed for one size may have content clipped or show white borders when printed on the other. Using margins of at least one inch on all sides minimizes compatibility problems between the two formats.
What are the dimensions of A4 paper in inches?
A4 paper measures 8.268 x 11.693 inches (often rounded to 8.27 x 11.69 inches). In millimeters, the exact dimensions are 210 x 297 mm. At 300 DPI for print, an A4 sheet is 2,480 x 3,508 pixels. At 72 DPI for screen, it is 595 x 842 pixels, which is the standard size you see when viewing an A4 PDF on screen.
What paper size is used for legal documents in the US?
In the US, legal documents such as pleadings, contracts, and court filings are traditionally printed on US Legal paper, which measures 8.5 x 14 inches (215.9 x 355.6 mm). Legal paper is 3 inches taller than Letter and accommodates longer documents without as many page breaks. Many US courts have specific formatting requirements including paper size, margins, font, and line spacing, so always check the court or jurisdiction rules before printing legal filings.
What is the difference between A3 and A4 paper?
A3 (297 x 420 mm, or 11.69 x 16.54 inches) is exactly twice the area of A4 (210 x 297 mm). Folding an A3 sheet in half along its longer dimension produces an A4 sheet. A3 is used for posters, brochures, spreads, architectural drawings, and any content that needs more space than A4 provides. It is roughly equivalent to the US Tabloid size (11 x 17 inches), though Tabloid is slightly wider and shorter. Most office laser printers handle A4 but not A3; a wide-format or A3 printer is required for A3 output.