CAD Paper Sizes Explained: ISO, ANSI and ARCH
CAD plotting commonly uses three paper families: ISO A-series, ANSI engineering sizes and ARCH architectural sizes. Choose the project standard first, then confirm that the selected printer or PC3 actually supports that physical sheet.
Start here — what you are going to do
Your goal: Recognize the main CAD paper standards before configuring a Layout.
Where to start: Check the project title block, client standard or previous issued sheet.
Beginner rule: Paper size is a physical-sheet decision. Do not change viewport scale to compensate for the wrong paper family.
Step by step — follow this in AutoCAD
Step 1 — Identify the paper family
Where: Project title block / issue standard.
Do this: Look for A1/A3, ANSI D/E, ARCH D/E1 or exact dimensions.
Check: You know which standard the project expects.
Step 2 — Open the Layout
Where: Bottom drawing tabs > production Layout.
Do this: Use the real sheet, not Model Space.
Check: The title block is visible.
Step 3 — Open Page Setup
Where: Output > Plot > Page Setup Manager > Modify.
Do this: Read Printer/Plotter and Paper Size.
Check: The current physical sheet is visible.
Step 4 — Match the exact dimensions
Where: Paper Size list.
Do this: Choose the required standard size.
Check: The paper matches the title block.
Step 5 — Check printable area
Where: Layout dashed boundary / Plot partial preview.
Do this: Keep critical border/text inside the printable region.
Check: No clipping is expected.
Step 6 — Preview
Where: Ctrl+P > Preview.
Do this: Check border, orientation and title block.
Check: The standard and Layout agree.
Beginner example
A1 (594 × 841 mm), ANSI D (22 × 34 in) and ARCH D (24 × 36 in) can all be used for large technical sheets, but they are not interchangeable. Similar purpose does not mean identical dimensions.
Understand what AutoCAD is doing
ISO A-series
| Size | Metric dimensions | Approx. inches |
|---|---|---|
| A0 | 841 × 1189 mm | 33.1 × 46.8 in |
| A1 | 594 × 841 mm | 23.4 × 33.1 in |
| A2 | 420 × 594 mm | 16.5 × 23.4 in |
| A3 | 297 × 420 mm | 11.7 × 16.5 in |
| A4 | 210 × 297 mm | 8.3 × 11.7 in |
ANSI engineering sizes
| Size | Inches | Approx. metric |
|---|---|---|
| ANSI A | 8.5 × 11 in | 216 × 279 mm |
| ANSI B | 11 × 17 in | 279 × 432 mm |
| ANSI C | 17 × 22 in | 432 × 559 mm |
| ANSI D | 22 × 34 in | 559 × 864 mm |
| ANSI E | 34 × 44 in | 864 × 1118 mm |
ARCH architectural sizes
| Size | Inches | Approx. metric |
|---|---|---|
| ARCH A | 9 × 12 in | 229 × 305 mm |
| ARCH B | 12 × 18 in | 305 × 457 mm |
| ARCH C | 18 × 24 in | 457 × 610 mm |
| ARCH D | 24 × 36 in | 610 × 914 mm |
| ARCH E | 36 × 48 in | 914 × 1219 mm |
| ARCH E1 | 30 × 42 in | 762 × 1067 mm |
The output device still controls the list
AutoCAD’s Paper Size list is filtered by the selected printer, plotter or PC3. A standard size can be perfectly valid and still be absent because the chosen device does not expose it.
Useful next guides: Paper Sizes & Margins · ISO A-Series Paper Sizes for CAD: A0 to A4 · ANSI Paper Sizes for CAD: A, B, C, D and E · ARCH Paper Sizes for CAD: A, B, C, D, E and E1 · AutoCAD Printable Area and Plot Margins Explained
Common problems and what to check first
| What you see | What may be causing it | Check this first |
|---|---|---|
| Expected size is missing | Selected device does not expose it | Check printer/PC3 first. |
| Title block is slightly too large | A near-size standard was substituted | Compare exact dimensions. |
| Border is clipped | Device printable area is smaller than paper | Check margins. |
| PDF is correct but paper is resized | Viewer/printer uses Fit or different paper | Use matching media and Actual Size. |
When you need a more repeatable workflow
Keep title blocks, named Page Setups and paper standards together in controlled DWT files. Avoid relying on users to remember a paper family at plot time.
Official Autodesk references
AutoCAD labels and available media can vary by release, driver and output device. These Autodesk pages document the core workflow used in this guide.
Frequently asked questions
Are A1 and ARCH D the same?
No. A1 is 594 × 841 mm; ARCH D is 24 × 36 in.
Why does AutoCAD show only some sizes?
The selected output device controls which media are available.
Should the title block match the selected paper?
Yes.
Explore more in CAD Paper Sizes, Margins & Printable Area.