USPS Package Restrictions
If you need to know how big your USPS parcel can be, we have all the numbers you need below.
What size and weight restrictions does USPS have?
The Predefined Package names are drawn from the EasyPost API, so you can better reference how each Predefined Package matches up dimensionally.
| Predefined Package Name | Dimensions | Weight |
|---|---|---|
| Card | Min: Min: Domestic: 5″ x 3 ½” x 0.007″ International: 5 ½” x 3 ½” x 0.007″
Max: 6″ x 4 ¼” x 0.016″ |
Must be a flat surface |
| Letter |
Min: Domestic: 5″ x 3 ½” x 0.007″ International: 5 ½” x 3 ½” x 0.007″ Max: 11 ½” x 6 ⅛” x ¼” |
Maximum weight is 3.5 oz. |
| Flat |
Min: 11 ½” x 6 ⅛” x ¼” (must exceed one of these dimensions) Max: 15″ x 12″ x 3/4″ |
Maximum weight is 13 oz. |
| Parcel |
Domestic: Maximum size for USPS Ground Advantage is 130″ in combined length and girth International: Maximum length + height + thickness combined = 36 inches |
Maximum weight is 70 lbs. |
| Flat Rate Envelope | 12 ½” x 9 ½” |
Domestic maximum weight is 70 lbs. International maximum weight is 4 lbs. |
| Flat Rate Legal Envelope | 15″ x 9 ½” |
Domestic maximum weight is 70 lbs. International maximum weight is 4 lbs. |
| Flat Rate Padded Envelope | 12 ½” x 9 ½” | Domestic maximum weight is 70 lbs.
International maximum weight is 4 lbs. |
| Flat Rate Gift Card Envelope | 10″ x 7″ | Domestic maximum weight is 70 lbs.
International maximum weight is 4 lbs. |
| Flat Rate Window Envelope | 10″ x 5″ |
Domestic maximum weight is 70 lbs. International maximum weight is 4 lbs. |
| Flat Rate Card board Envelope | 12 ½” x 9 ½” |
Domestic maximum weight is 70 lbs. International maximum weight is 4 lbs. |
| Small Flat Rate Envelope | 12 ½” x 9 ½” |
Domestic maximum weight is 70 lbs. International maximum weight is 4 lbs. |
| Small Flat Rate Box | 8 ⅝” x 5 ⅜” x 1 ⅝” | Maximum weight is 70 lbs. |
| Medium Flat Rate Box | 11″ x 8 ½” x 5 ½” | Maximum weight is 70 lbs. |
| Large Flat Rate Box | 12″ x 12″ x 5 ½” | Maximum weight is 70 lbs. |
| Soft Pack | The longest dimension may not exceed 18 inches. Cubic rating will be applied using Length and Width only. See more details on the USPS Cubic Pricing page. | Maximum weight is 20 lbs. |
Note: Drag table to view all columns
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