A3 compared with A4
A4 vs A3
A4 measures 210 × 297 mm (8.27 × 11.69 in); A3 measures 297 × 420 mm (11.69 × 16.54 in).A3 is 87 mm wider. A3 is 123 mm taller.
Try a comparison
AFirst paper
210 × 297 mm
BCompare with
297 × 420 mm
All measurements update together.
At a glance
Both sheets shown at the same scale
A4PortraitA3Portrait
Proportional preview · not actual print size
A3 minus A4
Scale A4 to fit inside A3
The details, side by side
A4 and A3: dimensions in the selected orientation.
| Measurement | AA4 | BA3 |
|---|---|---|
| Width | 210 mm | 297 mm |
| Height | 297 mm | 420 mm |
| Area | 62370 mm² | 124740 mm² |
| Aspect ratio (width : height) | 1 : 1.41 | 1 : 1.41 |
Print scale uses the orientations shown above and excludes printer margins and bleed. Rotate a sheet to explore a different fit.
Area difference
A3 has 100% more area than A4, using A4 as the baseline.
Print scaling
A4 onto A3: 141%. A3 onto A4: 70%. These portrait-to-portrait scales exclude printer margins and bleed.
Enter the percentage in your print dialog's Custom Scale field, select the destination paper size, and check the preview for the printer's unprintable margins.
Aspect ratios
A4: 1.41:1; A3: 1.41:1 (long edge to short edge, rounded to two decimal places).
Which should you use?
Choose A4 when your document template or recipient requests it, and A3 when that format is required. A3 offers more room for layouts and diagrams; the smaller sheet takes less space for compact documents.
A4 vs A3 FAQ
What is the size difference between A4 and A3?
A4 measures 210 × 297 mm (8.27 × 11.69 in); A3 measures 297 × 420 mm (11.69 × 16.54 in). A3 is 87 mm wider. A3 is 123 mm taller.
How does A3 compare with A4 in area?
A3 has 100% more area than A4, using A4 as the baseline.
What scale prints A4 on A3, and vice versa?
A4 onto A3: 141%. A3 onto A4: 70%. These portrait-to-portrait scales exclude printer margins and bleed.
Do A4 and A3 have the same aspect ratio?
A4: 1.41:1; A3: 1.41:1 (long edge to short edge, rounded to two decimal places). Their proportions are approximately the same, allowing for whole-millimetre rounding.