A3 paper size
A3 paper is 297 × 420 mm (11.69 × 16.54 in) — exactly twice an A4 sheet.
297 × 420millimetres
11.69 × 16.54inches
A3 vs A4
| Size | mm | inches |
|---|---|---|
| A3 | 297 × 420 mm | 11.69 × 16.54 in |
| A4 | 210 × 297 mm | 8.27 × 11.69 in |
The A-series doubles or halves cleanly: each size up doubles the area, each down halves it, keeping the same 1:√2 shape.
Frequently asked questions
What size is A3 paper?
297 × 420 mm (11.69 × 16.54 in).
Is A3 double A4?
Yes — two A4 sheets side by side make an A3 (297 × 420 mm).