United States Postal Service
USPS size and weight limitations differ depending upon destination, but generally 108" (calculated by adding the total outside dimensions, length + width + height) and 70 lbs. is the maximum. Go to www.usps.com for specifics. Cases2Go uses USPS for shipments to APO addresses whenever possible.
United Parcel Service
UPS dimensional limitation is 160", calculated as length + girth of package (length + 2x depth + 2x height), with a maximum weight per package of 150 lbs. UPS uses several other dimensional factors when computing ground rates, as well as dimensional weight rules (see below) when computing air rates - go to www.ups.com for specifics.
Federal Express and other Freight Forwarders
FedEx and other air freight forwarders have no size or weight limitations, other than the freight must be no larger or heavier than the capacity of a Boeing 747 freighter. All air carriers calculate their rates based on actual or dimensional weight, whichever is greater.
Dimensional weight is calculated by multiplying the three outside dimensions of the package (or pallet) and then dividing by 194 (domestic shipments), or 166 (international shipments). If the dimensional weight exceeds the actual weight, it becomes the chargeable weight for the shipment.
Truck (Common) Carriers
Truck carriers have very high weight limitations and size limitations of 102" wide x 102" high. Rates are computed based on the NMFC (National Motor Freight Classification) system.