What size is a postcard?
The most commonly mailed postcard size is approximately 4″ x 6″.
The Universal Postal Union (UPU) has given the following minimum and maximum sizes for postcards:
- Minimum: 140 x 90 mm OR 5.51 x 3.54 in
- Maximum: 35 x 120 mm OR 9.25 x 4.72 in
