Quote Originally Posted by waredu View Post
I think people have dimensional weight misunderstood.

Fedex will use the higher of actual weight or dimensional weight for calculating shipping charges. See their calculator here [fedex.com/be/tools/dimweight]FedEx - Dimensional weight calculator[/url]

So, if I have an 18x18x20 box that weighs 69 pounds, I will pay for 69 pounds. But if I have the same size box and it only weighs 30 pounds I will be charged for shipping the dimensional weight of 47 pounds.

Big, light packages take up room - small, heavy packages take up weight. Their trucks and planes only have so much space and can only carry so much - so they charge you accordingly (does your package take up more weight or more space?).

waredu

Your dimensional calculations are right for international shipments. The divisor for domestic ground and express is slightly higher at 166. So to calculate dimensional weight you multiply L x W x H and divide by 166. This will give you the dimensional weight that your box will be charged. For international shipments the same formula applies but you divide by 139 rather than 166. So for a 18x18x20 box, the dimensional weight would be rated at 40 lbs not 47 lbs.

If the box is less than 5,184 cubic inches dimensional weight does not apply and the package will rate at actual weight. Dimensional weight applies as soon as the cubic inches exceed 5,184. In 2015 however this will change and FedEx will start applying dimensional weight to every package even if it is under 5,184 cubic inches.