If you give inaccurate dimensions and/or don’t pay the DIM weight rate (when it applies), you’ll pay a dimension-noncompliance fee.

If the DIM weight is greater than the actual package weight, you’ll need to pay the DIM weight price.Multiply Length x Width x Height and divide by 166 to get the DIM weight in pounds.

If your package is larger than 1 cubic foot (1,728 cubic inches): Dimensional (DIM) weight rates apply to large, lightweight packages.

Maximum combined length and girth (girth is the distance around the thickest part) is 108″.

You’ll need to measure your package to make sure it meets the size standards.

Use your own box and pay by weight and zone (distance):

Use USPS Priority Mail Express Mailing Boxes that come in standard sizes so you don’t have to worry about measuring them.

Pay for your package based on how much it weighs and how far it’s going (the zone).

Use USPS Priority Mail Express Mailing Boxes and pay by weight and zone (distance):

When sealing a Priority Mail Express Flat Rate Envelope, the container flaps must be able to close within the normal folds.

Pay the same price for mailpieces weighing up to 70 lbs going anywhere in the U.S.

Weight, Size, & Shape Requirements Use USPS Priority Mail Express Flat Rate Envelopes and pay one price:

Usps flat rate boxes medium