Paper Size Comparison
Compare ISO A/B/C, US, and JIS B paper sizes with visual comparison and unit conversion
Visual Size Comparison
Size Chart
| Dimensions | Width | Height |
|---|---|---|
| A0 | 841 mm | 1189 mm |
| A1 | 594 mm | 841 mm |
| A2 | 420 mm | 594 mm |
| A3 | 297 mm | 420 mm |
| A4 | 210 mm | 297 mm |
| A5 | 148 mm | 210 mm |
| A6 | 105 mm | 148 mm |
| A7 | 74 mm | 105 mm |
| A8 | 52 mm | 74 mm |
| A9 | 37 mm | 52 mm |
| A10 | 26 mm | 37 mm |
🌐 Default Paper by Country
🇺🇸 US, Canada, Mexico, Philippines → Letter (8.5 × 11 in)
🌍 Most other countries → A4 (210 × 297 mm)
The Logic Behind A and B Paper Sizes
The math of the A series (ISO 216)
A0 is exactly 1 m², and every A-series sheet has a 1:√2 aspect ratio. The magic of that ratio: fold any sheet in half and the proportions stay identical — A4 halved is exactly A5. That's why photocopier scaling (A4→A3 at 141%, A4→A5 at 71%) works without distortion.
Sizes you'll actually meet
- A4 (210×297mm): the world's document standard
- A3: drawings, spreads
- A5: planners, booklets
- B series: fills the gaps between A sizes on the same principle — B5 notebooks, B6 manga.
North America is different
The US and Canada use Letter (216×279mm / 8.5×11") and Legal. Letter is wider and shorter than A4, which is why margins get clipped when documents cross the Atlantic. When printing PDFs from abroad, check the 'fit to page' setting.
Frequently Asked Questions
Related Tools
Sources & References
Content last reviewed: 2026-08-22