# Dimensional Weight Explained

Dimensional weight is something that affects all of our customers, and as a result we’ve gotten our fair share of questions on the subject. The concept of dimensional weight can be very foreign at first, but here is an explanation that should make the idea seem more natural — although it will not make you like it any more.

When shipping carriers like FedEx, UPS, or DHL load up their cargo planes to transport packages internationally, every square centimeter or inch of that plane’s storage and every kilogram or pound of that plane’s weight bearing limit has a value. The two limited resources of the plane are cargo hold size and cargo hold weight limits, and the carriers have priced out the expected value of a completely full cargo hold. When it’s full, either the space is all filled or the maximum weight limit is reached, and they want to make sure that a certain postage profit has been achieved. For that reason they have created dimensional weight calculations to determine postage based on size rather than actual weight.

It’s easy to understand that the postage for an incredibly heavy item would cost a lot more than a really light item. It is also generally the case the that larger a parcel is, the heavier it is. Sometimes though, a parcel is larger than the weight would suggest. In these cases, the shipping carriers calculate the postage they are going to charge based on the size rather than the weight of the package. These calculations determine the “Dimensional Weight.” In those cases where the Dimensional Weight formula returns a greater number than the actual weight, the “Dimensional Weight” is used just as if it were the actual weight for determining the postage due.

Vyking Ship uses the United States Postal Service (USPS) and FedEx for our shipments because we’ve found they offer the best mix of rates for all package sizes and weights. USPS does not use dimensional weight, but there are stricter maximum size limitations and rates are based solely on weight. FedEx, on the other hand, will always use the greater of the two weights: actual or dimensional, when they provide us with postage quotes.

Here is FedEx’s calculator to help you determine what a package’s dimensional weight is: http://www.fedex.com/be/tools/dimweight.html. Each company that uses dimensional weight has its own calculation, so FedEx’s final calculations may differ from others.

Got more questions on dimensional weight? Get in touch with us. Email support@vykingship.com, reach out to our live chat or call 952-941-2452.

3 replies
1. Anonymous says:

I am aware precisely how you feel. Great post.

2. john says:

I’ve used a package forwarding website (not vykingship) that doesn’t show dimensional weight cost until my parcels have reached their warehouse. The resulting total shipping cost was unexpected. My clothing items weren’t boxed, fortunately, so they were only charged for 0.5kg of dimensional weight (it still costed an additional \$20).

• Clinton LaHue says:

It is unfortunate that there are still so many forwarding companies out there that don’t incorporate dimensional weight into their postage calculators or mislead their potential customers by giving a weight vs postage chart without explaining the need to also calculate the dimensional weight. If you read our “How to Choose and International Package Forwarding Company” post, I make specific mention in there about this problem and what to look out for when it comes to a company’s claims with regard to postage rates.