A3 Paper Size
A3 paper size measures 297 × 420 mm. The Dimensions of A3 Paper are 11.69 by 16.54 inches, 29.7 by 42.0 centimetres, 3508 by 4961 pixels at 300 DPI, and 842 by 1191 points. It is half of A2. Its most common use is spreadsheets.
A3 measures 297 millimetres wide and 420 millimetres tall.
Dimensions of A3 Paper
| Unit | Width | Height | Width × height | Copy |
|---|---|---|---|---|
| Millimetres (mm) | 297 | 420 | 297 × 420 mm | |
| Centimetres (cm) | 29.7 | 42.0 | 29.7 × 42.0 cm | |
| Metres (m) | 0.297 | 0.42 | 0.297 × 0.42 m | |
| Inches (in) | 11.69 | 16.54 | 11.69 × 16.54 in | |
| Feet (ft) | 0.97 | 1.38 | 0.97 × 1.38 ft | |
| Points (pt) | 842 | 1191 | 842 × 1191 pt | |
| Picas (pc) | 70.2 | 99.2 | 70.2 × 99.2 pc | |
| Pixels at 72 DPI | 842 | 1191 | 842 × 1191 px | |
| Pixels at 150 DPI | 1754 | 2480 | 1754 × 2480 px | |
| Pixels at 300 DPI | 3508 | 4961 | 3508 × 4961 px | |
| Pixels at 600 DPI | 7016 | 9921 | 7016 × 9921 px |
Pixel counts follow from the resolution: pixels = millimetres ÷ 25.4 × DPI. More on the DPI and pixels page.
A3 Paper Format
A3 is half of A2 and folds in half to A4. One A3 sheet tiles into 2 × A4, 4 × A5, 8 × A6. Put A3 next to another size in the comparison tool.
A3 Size in Millimeters (mm)
A3 is 297 × 420 mm (297 mm wide, 420 mm tall). Millimetres are the base unit of ISO 216, so these are the exact figures paper mills and print shops cut to. Page-setup dialogs outside the US expect ISO A-series sizes entered in mm.
A3 Size in Centimeters (cm)
A3 is 29.7 × 42.0 cm. Centimetres are the handy unit for checking a sheet against a school ruler or giving a rough size; the figure is the millimetre value divided by ten.
A3 Size in Inches
A3 is 11.69 × 16.54 inches. Inches come up when A3 is opened in US-configured software or compared with Letter and Legal. One inch is fixed at 25.4 mm.
A3 Size in Pixels
At 300 DPI A3 is 3508 × 4961 px; at 72 DPI it is 842 × 1191 px. Pixel dimensions are what you type into the new-document box in Photoshop, GIMP or Figma, and they scale with the DPI you choose.
A3 in Pixels at 72 DPI (Screen)
A3 is 842 × 1191 px at 72 DPI. This is the legacy screen resolution, used for on-screen mockups, web previews and wireframes where physical print size is not the point.
A3 in Pixels at 300 DPI (Print)
A3 is 3508 × 4961 px at 300 DPI. 300 DPI is the print-quality benchmark, so set an A3 canvas to this pixel count for anything going to a commercial or a good home printer.
A3 Size in Points (pt)
A3 is 842 × 1191 points. Points are the unit of PDF, InDesign and LaTeX page geometry, where 72 points make one inch. A page set to 842 by 1191 pt exports as A3.
A3 Shape and Area
| Aspect ratio | 1 : 1.414 (√2) |
|---|---|
| Area | 0.125 m² · 124,740 mm² |
| Diagonal | 514.4 mm · 20.25 in |
| ISO 216 tolerance | ± 2 mm each side |
| Closest US size | Tabloid |
| Governing standard | ISO 216:2007 |
Frequently Asked Questions
What is A3 Paper Size?
A piece of A3 paper measures 297 × 420 mm (11.69 × 16.54 in). It is one of the ISO 216 A-series sizes, made by folding A2 in half, and it folds again to make A4.
What are the Uses of A3 Paper?
A3 is used for printed spreadsheets and schedules, magazine and layout proofs, classroom drawing paper.
How long is a piece of A3 paper?
A3 is 420 mm long on the longer edge and 297 mm on the shorter edge, which is 42.0 cm by 29.7 cm.
How long is A3 paper in inches?
The long edge of A3 is 16.54 inches and the short edge is 11.69 inches.
How long is a piece of A3 paper in cm?
A3 is 42.0 cm long by 29.7 cm wide.
A Paper Sizes
✓ Dimensions per ISO 216:2007; unit values derived by formula. Reviewed . Editorial Process →