A3 to A4 Conversion
A3 is exactly double A4. Folding an A3 sheet in half gives you an A4 sheet — this is the fundamental rule of the ISO 216 standard.
A3 (Original)
A3
297 × 420 mm
11.7 × 16.5 in
11.7 × 16.5 in
A4 (Result)
A4
210 × 297 mm
8.3 × 11.7 in
8.3 × 11.7 in
📊 A3 vs A4 Quick Facts:
• Ratio: 2 A4 sheets = 1 A3 sheet
• Fold: A3 folded in half gives A4
• Scale Factor: 70.7% (divide by √2)
• Uses: A3 for posters, A4 for documents
• Ratio: 2 A4 sheets = 1 A3 sheet
• Fold: A3 folded in half gives A4
• Scale Factor: 70.7% (divide by √2)
• Uses: A3 for posters, A4 for documents
📏 Complete Dimensions
| Unit | A3 | A4 |
|---|---|---|
| Millimetres | 297 × 420 mm | 210 × 297 mm |
| Centimetres | 29.7 × 42.0 cm | 21.0 × 29.7 cm |
| Inches | 11.7 × 16.5 in | 8.3 × 11.7 in |
| Pixels @ 72 DPI | 842 × 1191 px | 595 × 842 px |
| Pixels @ 300 DPI | 3508 × 4961 px | 2480 × 3508 px |
| Pixels @ 600 DPI | 7016 × 9921 px | 4961 × 7016 px |
🎨 Common Uses
- A3: Posters, presentation boards, large diagrams, spreads
- A4: Letters, documents, magazines, forms, standard printing
🔁 Related Conversions
- A3 to A2 – Double the size
- A3 to A5 – Quarter size
- A3 to Pixels – Digital conversion
- A4 to A3 – Reverse conversion
- A4 to Pixels – A4 pixel values
- A4 to A5 – Halve A4
❓ Frequently Asked Questions
Is A3 double A4? Yes — A3 is exactly double the area of A4.
How do I convert A3 to A4? Either fold the A3 sheet in half, or scale down to 70.7% when printing.