Construction drawings use three families of sheet sizes. Most of the world uses the ISO A series (A0, A1, A2, A3, A4), where each size is half of the one before. The US uses ARCH sizes for architectural drawings (ARCH A to ARCH E, with ARCH D at 24 × 36 inches the most common) and ANSI sizes for engineering drawings (ANSI A to ANSI E, based on the 8.5 × 11 inch letter sheet). The most common full-size drawing sheets are A1 outside the US and ARCH D (24 × 36 in) inside it.
ISO A series (international)
| Size | Millimetres | Inches (approx.) | Typical use |
|---|---|---|---|
| A0 | 841 × 1189 | 33.1 × 46.8 | Large site plans, presentation boards |
| A1 | 594 × 841 | 23.4 × 33.1 | Standard full-size drawing sheet |
| A2 | 420 × 594 | 16.5 × 23.4 | Smaller projects, details |
| A3 | 297 × 420 | 11.7 × 16.5 | Half-size sets, review prints, reports |
| A4 | 210 × 297 | 8.3 × 11.7 | Sketches, specifications, documents |
Every A size has the same proportion (1 : √2), so an A1 drawing printed on A3 is exactly a quarter of the area and half the scale: 1:100 @ A1 becomes 1:200 @ A3.
ARCH sizes (US architectural)
| Size | Inches | Millimetres (approx.) | Typical use |
|---|---|---|---|
| ARCH A | 9 × 12 | 229 × 305 | Sketches, small details |
| ARCH B | 12 × 18 | 305 × 457 | Half-size of ARCH D, small sets |
| ARCH C | 18 × 24 | 457 × 610 | Smaller projects |
| ARCH D | 24 × 36 | 610 × 914 | Standard full-size architectural sheet |
| ARCH E1 | 30 × 42 | 762 × 1067 | Larger projects |
| ARCH E | 36 × 48 | 914 × 1219 | Large plans and site plans |
ANSI sizes (US engineering)
| Size | Inches | Millimetres (approx.) |
|---|---|---|
| ANSI A | 8.5 × 11 | 216 × 279 |
| ANSI B | 11 × 17 | 279 × 432 |
| ANSI C | 17 × 22 | 432 × 559 |
| ANSI D | 22 × 34 | 559 × 864 |
| ANSI E | 34 × 44 | 864 × 1118 |
ANSI B (11 × 17 in, also called tabloid or ledger) is the usual half-size print in US offices, even for architectural sets drawn on ARCH D.
Which size should a drawing set use?
- Use one sheet size for the whole set. Mixed sizes make printing, binding and scaling harder.
- Choose the size from the largest plan at its intended scale, plus room for the title block.
- Write the paper size next to the scale in the title block ("1:100 @ A1"), so anyone printing smaller knows the scale changed.
- Check what the authority or client requires. Many permit portals and public clients specify sheet sizes for submissions.
Printing large sheets from a PDF
A1 and ARCH D sheets need a plotter for full size; on an office printer you print a reduced copy at a known ratio. In Ncored, the PDF editor we built in our architecture studio, printing supports paper sizes up to A0 and custom sizes, with scaling and page ranges, and your markups print with the drawing. It runs on Windows and Mac. See print drawings to scale and the paper size reference.
Frequently asked questions
What size is an A1 drawing?
594 × 841 mm, about 23.4 × 33.1 inches.
What is the standard size of architectural drawings in the US?
ARCH D, 24 × 36 inches, with 11 × 17 inch half-size prints for review.
Is ARCH D the same as ANSI D?
No. ARCH D is 24 × 36 inches; ANSI D is 22 × 34 inches.
What is the closest US size to A1?
ARCH D (24 × 36 in) is the closest in use, though the proportions differ, so a sheet does not convert exactly without margins.
Related: architectural scales explained, architectural title block guide, architectural sheet numbering.