Letter ↔ A4 Paper Size Converter
Convert between Letter and A4 paper sizes with visual comparison
8.5" × 11" (216 × 279 mm)
Letter (US)
↔
8.27" × 11.69" (210 × 297 mm)
A4 (International)
Letter Size (US)
93.5 in²
A4 Size (International)
96.7 in²
Size Comparison Result
Letter is 3.5% smaller than A4
A4 is taller and narrower than Letter paper
Letter Size
A4 Size
Similar
Size Difference
3.5%
Width Ratio
1.03:1
Height Ratio
0.94:1
Area Difference
3.2 in²
📄 Letter vs A4 Paper Sizes
Letter Size (US Standard)
- Dimensions: 8.5 × 11 inches
- Metric: 216 × 279 mm
- Usage: United States, Canada, Mexico
- Aspect Ratio: 1.294:1
A4 Size (ISO Standard)
- Dimensions: 8.27 × 11.69 inches
- Metric: 210 × 297 mm
- Usage: Most countries worldwide
- Aspect Ratio: 1.414:1 (√2:1)
Key Differences
- A4 is taller and narrower than Letter
- Letter is wider and shorter than A4
- A4 has √2 aspect ratio (folds perfectly in half)
- Letter has 1.294:1 aspect ratio
Common Issues
- Printing margins may be cut off
- Documents may need reformatting
- Scaling required for accurate printing
- Check printer settings before converting
📊 Paper Size Comparison Table
| Measurement | Letter Size | A4 Size | Difference |
|---|---|---|---|
| Width (inches) | 8.5 in | 8.27 in | Letter is 2.7% wider |
| Height (inches) | 11 in | 11.69 in | A4 is 6.3% taller |
| Width (mm) | 216 mm | 210 mm | Letter is 6 mm wider |
| Height (mm) | 279 mm | 297 mm | A4 is 18 mm taller |
| Area (in²) | 93.5 in² | 96.7 in² | A4 is 3.5% larger |
| Aspect Ratio | 1.294:1 | 1.414:1 | Different proportions |
🖨️ Printing Tips
- Scale to fit: Most printers have "scale to fit" or "fit to page" option
- Check margins: A4 to Letter may cut off bottom content
- Use PDF: Convert documents to PDF for better size preservation
- Test print: Always print a test page first
- Adjust layout: Consider changing page orientation if needed
❓ Frequently Asked Questions
Q: Can I print A4 documents on Letter paper?
A: Yes, but you may need to use "scale to fit" or "shrink to fit" option in your printer settings. Some content at the bottom may be cut off.
Q: Which is larger, Letter or A4?
A: A4 is slightly larger in total area (96.7 in² vs 93.5 in²). A4 is taller but narrower than Letter.
Q: Why does A4 use √2 aspect ratio?
A: The √2 (1.414:1) aspect ratio allows A4 paper to be folded in half perfectly, creating A5 size with the same proportions.
Q: What countries use Letter size?
A: Letter size is primarily used in the United States, Canada, Mexico, and a few other countries. Most of the world uses A4.