Dimensional weight definitions have changed over the past two years.  First, in order to fall in the billing category of dimensional weight shipping, your box size needed to be larger than three cubic feet.  As of 2015, dimensional weight for UPS and FedEx applies to all packages, international and domestic alike.  Now, the billable shipping rate is the greater of either the dimensional weight, or the actual weight of the package.

The need for dimensional weight billing came from the large parcel carriers realizing they were not able to move large, lightweight packages without losing money.  Dimensional weight calculations ensure the shipper is using the most effective packaging methods and keeping sizes to a minimum, and while also ensuring the carriers are able to maximize the space on their vehicles.

In this post, we will walk you through the few steps to take in order to calculate dimensional weight of a package for shipping.

Traditional Shipping Weight Calculation

As mentioned above, traditionally, calculating the billing rate for shipping was as easy as weighing the package on a scale and entering that information into the carrier’s system.  Using their rate calculators based on destination address, the carrier would provide a billing rate for your package.

Calculating Dimensional Weight

There are really three simple steps in calculating dimensional weight.

Step One:  Calculate the cubic size of your package by multiplying the length times the width times the height (LxWxH) of the package.  Make sure you round any fractions up to the nearest whole inch.

Step Two:  Divide the cubic size of your package by 139 to determine the dimensional weight.  Increase all fractions up to the nearest whole pound.

Step Three: Determine whether the dimensional weight or the actual weight of the package is greater.  The greater of the two packages is the billable rate.

Large Packages

Parcel carriers also use calculations for “large packages” to distinguish a large package from a standard package size.  To see if your package qualifies as a large package, follow the simple calculations below.

Find the girth: Length of the package, plus two times the width, plus two times the height. (L+2W+2H)

If this calculation equates to a size of at least 130 inches, and less than the max size of 165, the package is considered a large package.  Most parcel carriers have a surcharge for large packages. Another limit on large packages is, they may not exceed 90 pounds.


UPS and FedEx have outlined their billable rate calculations on their websites if you need more information.  These new calculations force shippers to think about the size of their shipping box, as well as the packaging material and the general weight of the package.  Most fulfillment centers will be able to help you optimize your shipping costs, in conjunction with their discounted parcel rates, a 3PL or fulfillment center will be able to help you achieve your growth goals with a degree of simplicity and assurance.