US Letter and A4 are two common paper sizes used in different regions of the world.
US Letter is the standard paper size used in the United States and some other countries. A4 is the standard paper size used in most countries outside of North America. It measures 8.27 inches by 11.69 inches (210 mm by 297 mm).
So, if you are from the United States, you would typically use US Letter, while A4 is more commonly used in other parts of the world.
| Paper Size | Inches | Millimeters | Centimeters |
|---|---|---|---|
| A4 | 8.3 x 11.7 in | 210 x 297 mm | 21.0 x 29.7 cm |
| A5 | 5.8 x 8.3 in | 148 x 210 mm | 14.8 x 21.0 cm |
| US Letter | 8.5 x 11 in | 216 × 279 mm | 21.6 × 27.9 cm |
| Legal | 8.5 x 14 in | 216 x 356 mm | 21.6 x 35.6 cm |
| A7 Card | 5 x 7 in | 127 x 178 mm | 12.7 x 17.8 cm |