Postage is charged by weight and distance. For lightweight large packages, a balloon rate may be charged instead.

Parcels addressed to zones 1-4 (including local) that weigh less than 20 pounds, but measure more than 84 inches (but not more than 108 inches) in combined length and girth are charged the applicable zone price for a 20 pound parcel.

Dimensional weight is applied to parcels addressed to zones 5-8 and that exceed 1 cubic foot (1,728 cubic inches) The dimensional weight represents the amount of space a package occupies in relation to its scale weight, therefore postage may be based on scale weight or dimensional weight, whichever is greater.

These are the calculations we use to determine pricing based on the measurements you provide.

Rectangular Packages
Balloon Rate - zones 1-4 (includes local)
(The maximum allowed for this rate is 108" and 70 pounds.)

Length + Girth = X"
Length is always the longest measurement. Girth is the measurement around the thickest part of the parcel.

Dimensional Weight - (zones 5-8)
Length x Width x Height = X / 194 = X pounds
If the result exceeds 1,728 cubic inches, divide the result by 194 and round up to the nearest whole inch to determine dimensional weight in pounds.*

Non-rectangular Packages
Balloon Rate - zones 1-4 (includes local)
(The maximum allowed for this rate is 108"" and 70 pounds.)

Length + Girth = X"

Dimensional Weight

Length x Width x Height = X(0.785) = X / 194 = X pounds
Before performing this calculation, round off length, width, and height. Multiply the result by 0.785 (*see above). If the dimensional weight exceeds 70 pounds, the mailer pays the 70 pound price.