Understanding the specific package sizes and dimensions for USPS services will help you make more informed decisions about how to ship your products. This guide outlines the requirements of girth, packaging, and dimensions for domestic services. By looking at each section separately, you can more accurately measure your shipment and determine what the cost will be.
Fees and surcharges may apply to Priority Mail, Priority Mail Express, and Ground Advantage shipments based on the package volume and dimensions.
Dimensional weight, also called DIM weight or volumetric weight, is a pricing method that uses an estimated weight calculated from the length, width, and height of a package divided by a specific divisor determined by the carrier. For certain carriers, like USPS, UPS, and FedEx, a shipment's billable shipping cost is calculated based on dimensional weight if that value is higher than the actual weight.
To ensure you are receiving accurate shipping quotes, we recommend that you always include a package's total weight and package dimensions.
Flat Rate packages are not affected.
If dimensions are not provided or if dimensions are inaccurate: A $1.50 fee will be added for packages that are greater than one cubic foot in volume or have a box length greater than 22 inches.
Enter Dimensions to Avoid Surcharges
When preparing a package for shipment, if the dimensions section is present, be sure to enter the size of your package to ensure an accurate rate and avoid post-shipping adjustments.
If packages have dimensions that exceed machinable sorting requirements, nonstandard sizing fees will apply as follows:
USPS Priority Mail and Priority Mail Express
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If the longest side of a package is more than 22 inches but less than 30 inches, a $4.00 surcharge will be applied
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If the longest side of a package is greater than 30 inches, a $15.00 surcharge will be applied
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If the volume of the package is greater than 2 cubic feet, a $30.00 surcharge will be applied*
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Packages with missing or incorrect package dimensions that result in any dimensions-based fees, a $1.50 surcharge will be applied
USPS Ground Advantage
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If the longest side of a package is more than 22 inches but less than 30 inches, a $4.00 surcharge will be applied*
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If the longest side of a package is greater than 30 inches, a $8.40 surcharge will be applied*
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If the volume of the package is greater than 2 cubic feet, a $18.00 surcharge will be applied*
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Packages with missing or incorrect package dimensions that result in any dimensions-based fees, a $1.50 surcharge will be applied*
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Does not apply to Media Mail.
Shipping dimensions are only used if you are sending a shipment in a custom box or envelope rather than in a carrier's flat-rate packaging. The shipment dimensions will affect the cost of the shipment, so accurate measurements are important.
Dimensional (cubic) pricing and dimensional (DIM) weight pricing are based on volume (length x width x height) rather than physical weight as the volume determines how much space the package takes up in the truck or airplane.
Length: The longest size of the package.
Width: The distance from one side to the other on the shortest part of the package.
Height: The distance from top to bottom of a standing package.
"Machinable" packages mean they are able to be sorted by a machine. If your package is larger than the machine is able to sort, it will be bumped into the next class of letters or packages, which often costs more money.
Machinable - Oversized vs Minimum dimensions
Oversized Priority Mail packages may be subject to dimensional pricing even when below the maximum 108" dimension.
Packages are also subject to minimum dimensions. No package may be smaller than 5" x 3.5" x 0.007". Machinable packages may not be smaller than 6" x 3" x 0.25".
Non-Machinable Surcharge Fee
Non-machinable packages may be subject to surcharge fees. Learn more about physical standards for parcels.
If you can answer “Yes” to any of the following questions, you may have a non-machinable package that will incur an additional fee.
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Is the package a strange shape?
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Does this package have improper postage or is the shipping address in a hard-to-see location?
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Is the package in an odd container?
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Can anything on my package get caught or tangled with other things?
Some domestic shipping supplies are offered for free through the USPS.
Click on the following options to order free boxes:
The following tables outline the maximum weights and dimensions for domestic package and envelope types offered through the USPS.
Package Type |
Service |
Max Weight |
Max Dimensions |
---|---|---|---|
Package |
Ground Advantage (formerly First-Class Package Service) |
15.9 oz |
22" x 18" x 15" |
Ground Advantage (Parcel Select Ground) |
70 lb |
Length + Girth < 130" |
|
Priority Mail |
70 lb |
||
Priority Mail Express |
70 lb |
Length + Girth < 108" |
|
Flat Rate Small Box |
Priority Mail |
70 lb |
8-5/8"(W) x 5-3/8"(L) x 1-5/8" (H) |
Flat Rate Medium Box |
Priority Mail |
70 lb |
(Top loading) Box 1= 11" (L) x 8-1/2"(W) x 5-1/2"(H) (Side loading) Box 2= 11-7/8"(L) x 3-3/8"(W) x 13-5/8"(H) |
Flat Rate Large Box |
Priority Mail |
70 lb |
12-1/4" (L) x 12" (W) x 6" (H) |