Paper Size Reference
Paper sizes follow international standards defined by ISO 216 (metric) or traditional US sizes. The ISO A series is the most common worldwide, with A4 being the standard letter size in most countries. The ISO B series provides intermediate sizes, and the C series defines envelope sizes. The United States uses different sizes: Letter (8.5 x 11 inches) is the standard business size. This reference provides complete tables of ISO A, B, and US paper sizes in both metric (millimetres) and imperial (inches) units.
ISO A Series (mm)
| Size | Millimetres | Inches |
|---|---|---|
| A0 | 841 x 1,189 | 33.1 x 46.8 |
| A1 | 594 x 841 | 23.4 x 33.1 |
| A2 | 420 x 594 | 16.5 x 23.4 |
| A3 | 297 x 420 | 11.7 x 16.5 |
| A4 | 210 x 297 | 8.3 x 11.7 |
| A5 | 148 x 210 | 5.8 x 8.3 |
| A6 | 105 x 148 | 4.1 x 5.8 |
| A7 | 74 x 105 | 2.9 x 4.1 |
ISO B Series (mm)
| Size | Millimetres | Inches |
|---|---|---|
| B0 | 1,000 x 1,414 | 39.4 x 55.7 |
| B1 | 707 x 1,000 | 27.8 x 39.4 |
| B2 | 500 x 707 | 19.7 x 27.8 |
| B3 | 353 x 500 | 13.9 x 19.7 |
| B4 | 250 x 353 | 9.8 x 13.9 |
| B5 | 176 x 250 | 6.9 x 9.8 |
| B6 | 125 x 176 | 4.9 x 6.9 |
US Paper Sizes
| Size | Inches | Millimetres |
|---|---|---|
| Letter | 8.5 x 11 | 216 x 279 |
| Legal | 8.5 x 14 | 216 x 356 |
| Ledger/Tabloid | 11 x 17 | 279 x 432 |
| Executive | 7.25 x 10.5 | 184 x 267 |
| Half Letter | 5.5 x 8.5 | 140 x 216 |
Notes on paper sizes
The ISO A series is defined by ISO 216, an international standard. A4 (210 x 297 mm or 8.3 x 11.7 inches) is the most common business paper size worldwide. The aspect ratio of all A series sizes is the square root of 2, which allows efficient sub-division. The B series provides intermediate sizes between A series. The C series defines envelope sizes. The United States uses different traditional sizes; Letter is the most common, followed by Legal for longer documents. The aspect ratio of Letter (8.5 x 11 inches) differs from ISO sizes.
Official sources
- ISO 216:2007: Paper and board. Trimmed sizes. Designation and dimensions. International Organization for Standardization.
Reviewed by the CalculatorHub team, edited by James Graham, 14 June 2026. See our methodology.