Dimensional Weight

Your package weighs 20 lbs., but UPS is charging you for 36 lbs. to ship your package.

What Gives?

Whether you operate a large-scale manufacturing facility that ships products by the truckload every day, or you’re a small-time eBay or Amazon seller who ships a few boxes a week, you have likely run into the dimensional weight issue in the past. Why are you being charged for more weight than the package actually weighs, and what exactly is Dimensional Weight?

Here’s an easy way to understand it.

Each truck or trailer that transports freight on the highway, each rail car on the train, each cargo hold on the plane or ship, has a limited amount of space, and a limit on the amount of weight that can be carried.

Federal law regulates how heavy trucks can be. More than that, the construction of the vehicle determines how much weight the vehicle can carry. The shipping company desires to maximize each load, within the legal limits, in order to maximize profitability. A truck that is only half-full does not produce the same revenue as a truck that is filled to capacity.

When people ship packages that are large and lightweight, the truck fills up quickly, but the weight remains low. If the shipper only charged for the actual weight, they wouldn’t make enough money on that truckload to cover costs. In the same way, if the packages were all small boxes filled with lead, the weight limit would be reached before the truck was even half full. The company may get paid well for the weight that they are hauling, but another truck would be needed to haul any additional products since this truck is already at the maximum weight allowed. So neither scenario is profitable for the shipping company.

In order to address these situations, the shippers charge “dimensional weight” for packages. This allows them to achieve an average revenue for each cubic foot of space in the transport vehicle. If someone ships huge boxes of air pillows that are very light weight, they will pay the dimensional rate for the space that their packages take up in the trailer. Now each truck or trailer, whether full of large lightweight boxes, or small heavy boxes, can achieve the same level of revenue and profitability for the shipper.

The Dimensional Weight Formula

Length x Width x Height / 139


34″ x 23″ x 23″ = 17,986 cubic inches

17,986 divided by 139 = 129.39

So even if the package only weights 30 lbs., you will be charged for 130 lbs. based on how large the box is.

Fixing Incorrect Dimensions on an Amazon Product Page

So what if the dimensions are wrong?

If you are a seller of a product and you believe that the dimensions are not correct on the product page, open a case with Amazon Seller Support and ask them to perform a CUBISCAN on the product in question. In most cases, within a few days they will weigh and measure the product and correct any errors on the page. Just remember, the Dimensional Weight charges are based on the PACKAGE that the item is shipped in, not the actual item.

Greg Purdy Photograph

About the Author

Greg Purdy is the founder and co-owner of Seller Essentials, the resource website for all things Ecommerce. He lives in Maryland with his wife and children.

Subscribe to Essential Updates

for more resources, tips, and strategies to help grow your online business.