Standard Shapes and Size Guideline Chart

Minimum size for Postcards and Letters. - 5" long x 3 1/2" high
Maximum size for Postcards. - 6' long x 4 1/4" high
Maximum size for Letters and minimum size for Large Envelopes. - 11 1/2" long x 6 1/8" high
1/4" Maximum thickness for Letters
3/4" Maximum thickness for Large Envelopes.
For Parcel Post, the maximum Length + Girth is 130"
For other services, the maximum Length + Girth is 108"
Length = longest side of parcel.
Girth = measurement around the parcel


Unusual Shapes and Sizes

Some mail requires additional postage because it is difficult to process on mail sorting machines. Visit usps.com or call 1-800-ASK-USPS for correct postage.
Square envelopes
Envelopes in which the address is written parallel to the short edge.
Tubes and rolls
Packages weighing more than 35 pounds.
Books/printed material more than 25 pounds.
Packages larger than 34" long, 17" wide, or 17" high.


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