A3 Paper Size
A3 measures 297 × 420 mm (11.69 × 16.54 inches) under the ISO 216 standard. Exactly twice the area of A4, A3 is the largest size supported by many office printers and is widely used for charts, small posters, and printing two A4 pages side by side.
What Size is A3 in Inches?
A3 is 11.69 × 16.54 inches (297 × 420 mm), exactly twice the size of A4 and similar to US Tabloid.
| Unit | Width | Height |
|---|---|---|
| Inches | 11.69 | 16.54 |
| Millimeters | 297 | 420 |
| Centimeters | 29.7 | 42.0 |
A3 in Pixels
Pixel dimensions depend on your target DPI (dots per inch). Higher DPI means more pixels and sharper print output. 300 DPI is the standard for commercial printing.
| DPI | Width (px) | Height (px) | Use |
|---|---|---|---|
| 72 | 842 | 1191 | Screen display, digital proofs |
| 150 | 1754 | 2480 | Draft printing |
| 300 | 3508 | 4961 | Standard commercial print |
| 600 | 7016 | 9921 | High-quality or fine art print |
Use our free Inches to Pixels converter or Millimeters to Pixels converter to calculate pixel dimensions at any DPI.
A3 with Bleed
When preparing files for commercial printing, add bleed — extra design area beyond the trim edge that gets cut off during finishing. The standard bleed for ISO sizes is 3 mm per side.
| Measurement | Width | Height |
|---|---|---|
| With bleed (mm) | 303 | 426 |
| With bleed (inches) | 11.93 | 16.77 |
| Pixels at 300 DPI (with bleed) | 3579 | 5031 |
Size Comparison
A3 is half of A2 and exactly twice A4. It is close in size to US Tabloid (11 × 17 inches), though A3 is slightly narrower and taller. Two A4 pages printed side by side fit exactly on one A3 sheet.
Common Uses
- Small posters and point-of-sale displays
- Architectural sketches and presentation boards
- Large restaurant and cafe menus
- Charts, graphs, and classroom materials
- Printing two A4 pages side by side for booklet spreads
Design Tips
- Many office multifunction printers support A3, making it accessible for in-house printing without commercial services.
- A3 is the standard choice for printing A4 booklet spreads — design your A4 pages, then impose them on A3 for saddle-stitch binding.
- At 300 DPI (3508 × 4961 px), A3 files are a comfortable size for most design applications and workflows.
- If your audience is in North America, note that US Tabloid paper (11 × 17 in) is close but not identical to A3. Confirm paper availability before committing.
Setting Up A3 Files
In Adobe InDesign or Illustrator, create a new document at 297 × 420 mm and add 3 mm bleed. Most professional layout tools include A3 as a standard preset. For collaborative or browser-based workflows, Figma with the Print for Figma plugin includes a built-in A3 preset with bleed, crop marks, and CMYK export.
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