A3 ↔ A4 Paper Size Converter
Convert between A3 and A4 paper sizes with scaling options
📚 A3 ↔ A4 Paper Size Details
A3 Paper Size
Dimensions: 297 × 420 mm
Area: 0.125 m²
Aspect Ratio: 1:√2 (≈1:1.414)
Common Uses: Posters, drawings, charts
A4 Paper Size
Dimensions: 210 × 297 mm
Area: 0.0625 m²
Aspect Ratio: 1:√2 (≈1:1.414)
Common Uses: Letters, documents, printing
Size Relationship
Scaling Factor: 70.7% (A3→A4)
Area Ratio: A4 = ½ A3 area
2 A4 sheets fit on 1 A3 sheet
Aspect Ratio: Same (1:√2)
ISO 216 Standard
Both A3 and A4 follow ISO 216 paper size standard
Each size is half the area of the next larger size
Consistent aspect ratio (1:√2)
Used worldwide except in North America
📏 Size Comparison
🔄 Conversion Methods
1. Fit to Page (Recommended)
Scales the entire A3 content to fit perfectly on A4 paper while maintaining aspect ratio.
2. Actual Size
Maintains original dimensions. When converting A3 to A4, content will be cropped since A4 is smaller.
3. Custom Scaling
Set any scale percentage between 10% and 200% for specific requirements.
📊 A Series Paper Size Chart
| Paper Size | Dimensions (mm) | Dimensions (in) | Area Ratio |
|---|---|---|---|
| A2 | 420 × 594 mm | 16.5 × 23.4 in | 200% of A4 |
| A3 | 297 × 420 mm | 11.7 × 16.5 in | 200% of A4 |
| A4 | 210 × 297 mm | 8.3 × 11.7 in | 100% (Standard) |
| A5 | 148 × 210 mm | 5.8 × 8.3 in | 50% of A4 |
| A6 | 105 × 148 mm | 4.1 × 5.8 in | 25% of A4 |
❓ Frequently Asked Questions
A: The scaling factor is approximately 70.7% (1/√2). This maintains the aspect ratio while fitting A3 content onto A4 paper.
A: Two A4 sheets fit perfectly on one A3 sheet when placed side by side along the longer dimension.
A: Yes, by scaling down to 70.7%. Most printers have a "fit to page" option that automatically scales A3 to A4.
A: A3 is twice the area of A4. A3 measures 297×420mm while A4 measures 210×297mm. A4 is standard letter size in most countries.