Dimensional Weight Explained: Understanding Fulfillment Pricing

At ShipBob, we price our fulfillment services as simply and straightforwardly as possible, with no hidden fees or nasty surprises when your bill arrives. We compare rates among all major carriers to save you time and money, so you can spend your time building your business instead of dealing with the hassles and expenses of self-fulfillment.

That said, we want to be transparent and give our clients as much information as possible about how pricing works. One major factor in the pricing of your shipments is dimensional weight. Read on to learn more about this pricing technique.

What is dimensional weight?

Dimensional weight, also called DIM weight, is a pricing technique used for commercial freight transfer, including courier and postal services. Since space on a delivery truck is limited, dimensional weight takes into account package density to determine shipping rates. Freight carriers calculate shipping charges based on whichever number is greater: the actual weight of the package or its calculated dimensional weight.

How is dimensional weight calculated?

Dimensional weight uses an estimated weight calculated from the length, width, and height of a package, using the longest point on each side. These measurements should take into account any bulges or misshapen sides — these irregularities can incur special handling fees if not incorporated into the initial calculations for dimensional weight.

When calculating dimensional weight, most shipping carriers ask us to round to the nearest whole number. If the width of your package is 12.50 inches or above, you’d round up to 13 inches; if it’s 12.49 inches or below, you’d round down to 12 inches.

Next, multiply those dimensions to get the cubic size of the package. For example, if your package is 30 inches by 12 inches by 12 inches, your package size is the product of these three measurements: 4,320 cubic inches.

Finally, the cubic size of the package is divided by a shipping factor. These shipping factors are numbers set by the major freight carriers, such as UPS and FedEx. These factors represent cubic inches per pound.

For example, the current dimensional factor for FedEx shipments both domestically and internationally is 139 cubic inches per pound. For our example above, you would divide 4,320 by 139 to get a dimensional weight of 31 pounds. If the actual weight of the package is less than 31 pounds, the freight carrier will charge based on a weight of 31 pounds; if the actual weight is over 31 pounds, pricing will be based on the actual weight.

We hope this article gives you some helpful insight into the world of shipping costs. Want to know how ShipBob can help your business take the hassle out of fulfilling ecommerce orders and managing inventory? Request a quote today.

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