A4 vs Letter — quick guide and real examples

# **A4 vs Letter — quick guide and real examples** Short version first: A4 is the international standard used by most of the world. Letter is the North American standard used in the US and Canada. They are close but not the same. That small difference matters for printing, resumes, forms, folders, and envelopes. **Sizes and math** A4: 210 × 297 mm (8.27 × 11.69 in). Aspect ratio is √2 so it scales cleanly to halves and doubles (A5, A3, etc.). Letter: 215.9 × 279.4 mm (8.5 × 11 in). Aspect ratio is not √2 so scaling changes proportions. **Why the ratio matters** A4 divides in half nicely into A5 while keeping the same proportions. That makes layout, copying, and scaling predictable in the ISO system. Letter does not split to the same proportional halves, so resizing between sizes often requires cropping or extra margins. **Practical printing notes** If you print an A4 file on Letter paper without adjustment, the top and bottom will be cropped or margins will change. Use “scale to fit” or select the correct paper size in print settings. For professional print jobs, export a PDF sized to the target paper to avoid surprises. For resumes or formal documents, use the paper size expected by the audience. In the US and Canada use Letter. In Europe, UK, Australia and most of the world use A4. **Examples and what each is good for** ``` A4 — good for ``` * Business letters and formal correspondence in most countries * * CVs and resumes outside North America * * Reports, proposals, and academic papers (many universities and journals use A4) * * Brochures or flyers sized to A4 or folded into A5 * * Notebooks and stationery sold in Europe and Asia * * Certificates printed on A4 stock * * Office printing, photocopying and forms where A-series paper sizes are standard ``` Letter — good for ``` * Business letters, resumes and cover letters in the US and Canada * School worksheets, teacher handouts and homework packets in North America * Office memos, internal reports and printed forms used by American businesses * Manuals and user guides produced for North American customers * Booklets made by folding Letter into half-letter (5.5 × 8.5 in) * Envelopes sized for US business mail such as #10 (fits a Letter folded into thirds) **Common stationery and envelope pairings** A4 folded once to A5 or into thirds fits common European envelopes (DL is for A4 folded in thirds). C4 fits A4 flat. Letter folded into thirds fits US #10 envelope. Half-letter (5.5 × 8.5) is common for small booklets. **Tips by use case** [Resumes](https://the-resume-writer.medium.com/): Use Letter for US/Canada employers. Use A4 for employers elsewhere. [Templates](https://www.canva.com/templates/): Create two versions if you send internationally. That avoids awkward margins or scaling. [Design files](https://www.instagram.com/thedesignfiles): Set your artboard to the target paper size from the start. Include bleed (usually 3 mm / 0.125 in) for commercial printing. [Printing at home](https://www.youtube.com/watch?v=_xOGHjR16Fc): Check printer settings and print a one-page test to confirm margins and scaling. [Digital sharing](https://www.digitalsharing.org/): PDF to the chosen paper size is safest. Include a short note if recipients might need a different size. **Quick comparison table** * Feature A4 Letter * Size (mm) 210 × 297 215.9 × 279.4 * Size (in) 8.27 × 11.69 8.5 × 11 * Best region Most of world US & Canada * Scales to halves cleanly? Yes No * Common use Reports, CVs, brochures Resumes, school handouts, US business mail