Reference
Paper size chart
Every standard size in one place: the ISO A, B and C families, the US traditional sizes, and the ANSI and ARCH engineering ladders — 48 sizes in millimetres, inches and 300 DPI pixels. Download the two-page PDF for the wall, or take the whole table as an open JSON dataset.
ISO 216 A-series
The worldwide document standard. A0 is derived from one square metre; every size is the previous one halved, rounded to whole millimetres, at a constant 1:√2 ratio.
| Size | Millimetres | Inches | Pixels @ 300 DPI | Notes |
|---|---|---|---|---|
| A0 | 841 × 1189 | 33.11 × 46.81 | 9933 × 14043 | |
| A1 | 594 × 841 | 23.39 × 33.11 | 7016 × 9933 | |
| A2 | 420 × 594 | 16.54 × 23.39 | 4961 × 7016 | |
| A3 | 297 × 420 | 11.69 × 16.54 | 3508 × 4961 | |
| A4 | 210 × 297 | 8.27 × 11.69 | 2480 × 3508 | |
| A5 | 148 × 210 | 5.83 × 8.27 | 1748 × 2480 | |
| A6 | 105 × 148 | 4.13 × 5.83 | 1240 × 1748 | |
| A7 | 74 × 105 | 2.91 × 4.13 | 874 × 1240 | |
| A8 | 52 × 74 | 2.05 × 2.91 | 614 × 874 | |
| A9 | 37 × 52 | 1.46 × 2.05 | 437 × 614 | |
| A10 | 26 × 37 | 1.02 × 1.46 | 307 × 437 |
ISO 216 B-series
The in-between sizes: each Bn is the geometric mean of An and A(n−1). Used for posters, books and passports where A-steps are too coarse.
| Size | Millimetres | Inches | Pixels @ 300 DPI | Notes |
|---|---|---|---|---|
| B0 | 1000 × 1414 | 39.37 × 55.67 | 11811 × 16701 | |
| B1 | 707 × 1000 | 27.83 × 39.37 | 8350 × 11811 | Common large-poster size |
| B2 | 500 × 707 | 19.69 × 27.83 | 5906 × 8350 | |
| B3 | 353 × 500 | 13.9 × 19.69 | 4169 × 5906 | |
| B4 | 250 × 353 | 9.84 × 13.9 | 2953 × 4169 | |
| B5 | 176 × 250 | 6.93 × 9.84 | 2079 × 2953 | Common book trim size |
| B6 | 125 × 176 | 4.92 × 6.93 | 1476 × 2079 | |
| B7 | 88 × 125 | 3.46 × 4.92 | 1039 × 1476 | |
| B8 | 62 × 88 | 2.44 × 3.46 | 732 × 1039 | |
| B9 | 44 × 62 | 1.73 × 2.44 | 520 × 732 | |
| B10 | 31 × 44 | 1.22 × 1.73 | 366 × 520 |
C-series envelopes (ISO 269)
Envelopes sized to take the matching A-sheet flat — each Cn is the geometric mean of An and Bn. The standard was withdrawn by ISO; its sizes remain what envelope makers sell.
| Size | Millimetres | Inches | Pixels @ 300 DPI | Notes |
|---|---|---|---|---|
| C0 | 917 × 1297 | 36.1 × 51.06 | 10831 × 15319 | |
| C1 | 648 × 917 | 25.51 × 36.1 | 7654 × 10831 | |
| C2 | 458 × 648 | 18.03 × 25.51 | 5409 × 7654 | |
| C3 | 324 × 458 | 12.76 × 18.03 | 3827 × 5409 | |
| C4 | 229 × 324 | 9.02 × 12.76 | 2705 × 3827 | Takes A4 flat |
| C5 | 162 × 229 | 6.38 × 9.02 | 1913 × 2705 | A4 folded once / A5 flat |
| C6 | 114 × 162 | 4.49 × 6.38 | 1346 × 1913 | A6 flat — greeting cards |
| C7 | 81 × 114 | 3.19 × 4.49 | 957 × 1346 | |
| DL | 110 × 220 | 4.33 × 8.66 | 1299 × 2598 | Business envelope — not a C-size, listed with the family it serves |
US traditional sizes
Inch-defined sizes that predate ISO 216 and remain the North American standard. Inch definitions mean exact whole-pixel values at every common DPI.
| Size | Millimetres | Inches | Pixels @ 300 DPI | Notes |
|---|---|---|---|---|
| US Letter | 215.9 × 279.4 | 8.5 × 11 | 2550 × 3300 | |
| US Legal | 215.9 × 355.6 | 8.5 × 14 | 2550 × 4200 | |
| Tabloid / Ledger | 279.4 × 431.8 | 11 × 17 | 3300 × 5100 | Ledger = same sheet, landscape |
| Half Letter | 139.7 × 215.9 | 5.5 × 8.5 | 1650 × 2550 | US planner size |
| Executive | 184.1 × 266.7 | 7.25 × 10.5 | 2175 × 3150 | |
| Government Letter | 203.2 × 266.7 | 8 × 10.5 | 2400 × 3150 | Pre-1980s US federal size |
| Junior Legal | 127 × 203.2 | 5 × 8 | 1500 × 2400 |
ANSI/ASME Y14.1
The formal US engineering ladder starting from Letter. Areas double each step, but the aspect ratio alternates between 1:1.294 and 1:1.545.
| Size | Millimetres | Inches | Pixels @ 300 DPI | Notes |
|---|---|---|---|---|
| ANSI A | 215.9 × 279.4 | 8.5 × 11 | 2550 × 3300 | = US Letter |
| ANSI B | 279.4 × 431.8 | 11 × 17 | 3300 × 5100 | = Tabloid |
| ANSI C | 431.8 × 558.8 | 17 × 22 | 5100 × 6600 | |
| ANSI D | 558.8 × 863.6 | 22 × 34 | 6600 × 10200 | |
| ANSI E | 863.6 × 1117.6 | 34 × 44 | 10200 × 13200 |
Architectural (ARCH)
The parallel US series for architectural drawings, in cleaner 3:4 / 2:3 ratios. ARCH B (12×18) is famously confused with ANSI B (11×17).
| Size | Millimetres | Inches | Pixels @ 300 DPI | Notes |
|---|---|---|---|---|
| ARCH A | 228.6 × 304.8 | 9 × 12 | 2700 × 3600 | |
| ARCH B | 304.8 × 457.2 | 12 × 18 | 3600 × 5400 | Not the same as ANSI B |
| ARCH C | 457.2 × 609.6 | 18 × 24 | 5400 × 7200 | |
| ARCH D | 609.6 × 914.4 | 24 × 36 | 7200 × 10800 | The standard US poster/frame size |
| ARCH E | 914.4 × 1219.2 | 36 × 48 | 10800 × 14400 |
Frequently asked questions
What is the most common paper size in the world?
Two answers, split by geography: A4 (210 × 297 mm) everywhere ISO 216 applies — most of the planet — and US Letter (8.5 × 11 in) in the United States, Canada and Mexico. Every other size on this chart orbits one of those two defaults.
What is the B-series actually used for?
The in-between jobs. Each Bn is the geometric mean of An and A(n−1), landing halfway between A-steps: B1 (707 × 1000 mm) is a common large poster, B5 (176 × 250 mm) a common book trim, and B7 is the ID-booklet size passports are built around.
How do C-series envelopes relate to A-series paper?
Each Cn is the geometric mean of An and Bn — just enough bigger than An that the sheet slides in flat. C4 takes A4 unfolded, C5 takes A4 folded once (or A5 flat), C6 takes A6. The defining standard, ISO 269, has been withdrawn, but the sizes remain what envelope manufacturers sell.
What is the difference between ANSI B and ARCH B?
A full inch on each axis: ANSI B is 11 × 17 in (Tabloid); ARCH B is 12 × 18 in. Two separate US ladders share the same letters — always confirm the series when a drawing is specified as "B size".
Why do ISO sizes have "ugly" pixel values while US sizes are exact?
DPI means dots per inch, so inch-defined sizes convert to whole pixels at every standard resolution (Letter at 300 DPI is exactly 2550 × 3300). Millimetre-defined ISO sizes almost never land on whole pixels and must round — A4 at 300 DPI is 2480 × 3508 after rounding.