US Envelope Paper Sizes
Canadian P series (CAN 2-9.60M). P4 ≈ Letter.
US Envelope Paper Sizes — dimensions in mm and inches
| Format | mm | inches |
|---|
| P5 | 140 × 215 | 5.51 × 8.46 |
| P4 | 215 × 280 | 8.46 × 11.02 |
| P3 | 280 × 430 | 11.02 × 16.93 |
| P2 | 430 × 560 | 16.93 × 22.05 |
| P1 | 560 × 860 | 22.05 × 33.86 |