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Dimensional weight Calculator

Dimensional weight, Explained.

Learn more about DIM Weight below!
What is Dimensional Weight?

Dimensional weight, also called DIM weight, is a pricing technique used for commercial freight transfer, including courier and postal services. Dimensional weight is computed by multiplying length times width times height.

Since the amount of space on a delivery truck is limited, dimensional weight takes into account package density to determine shipping rates. So even if you have a lightweight package, it could be worth it to calculate DIM.

Freight carriers like USPS, Fedex, or UPS calculate shipping charges based on whichever number is greater: the actual weight of the package or its calculated dimensional weight. Whichever is higher becomes your billable weight.

How to calculate dimensional weight (DIM).

To calculate dimensional (DIM) weight, multiply the length, width, and height of a package, using the longest point on each side. Then, divide the cubic size of the package in inches by the DIM divisor to calculate the dimensional weight in pounds.

Note: For non-square packages, you would take the longest dimension on each side and round up.

Steps to calculate dimensional weight

1. Measure the length, width, and height of a package. These measurements should take into account any bulges or misshapen sides, as irregularities can incur special handling fees if not incorporated into the initial calculations for dimensional weight.

2. You'll want to round up all your results to the nearest whole number.

3. Next, multiply those package dimensions to get the cubic size of the package. For example, if your package is 30 inches by 12 inches by 12 inches, by multiplying these, your result should be 4,320 cubic inches.

4. Finally, the cubic size of the package is divided by a dimensional factor, also called a DIM divisor. DIM divisors are numbers set by the major freight carriers, such as UPS and FedEx. These factors represent cubic inches per pound.

The current DIM divisor used by FedEx and UPS, for example, for both domestic and international shipments is 139. Using our example above, you would divide 4,320 by 139 to get a dimensional weight of 31 pounds.


Here’s how a shipping carrier would charge for the package in this example:

  • If the actual weight of the package is less than 31 pounds (e.g., 20 pounds), the freight carrier will charge for the dimensional weight of 31 pounds since it is the greater number.

  • If the actual weight of the package is more than 31 pounds (e.g., 40 pounds), dimensional weight pricing will be based on the actual weight, not the dimensional weight.

The carriers will always charge based on the highest result (dim or actual weight). On some of your invoices you may notice the words "Billable weight" which their way to tell us, the highest of the two is "X" in that case.

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