How to Optimize Dimensional Weight to Reduce Shipping Costs

Package weight is one of the key factors affecting shipping costs, along with shipping zone (i.e., the distance the package must travel) and speed. Although there is little you can do to change your package’s gross weight, you can optimize its dimensional weight, which will also optimize your shipping costs.

The gross weight of a package is the total weight of its contents, filler, and box. In contrast, dimensional weight, also known as DIM or volumetric weight, is a calculated value that reflects how much space a package occupies relative to its gross weight. Shipping companies introduced dimensional weight to more appropriately charge for lightweight but bulky packages.

When shipping a package, carriers determine its actual and dimensional weights, then charge based on the higher value. Small packages that are heavy for their size are typically charged by gross weight, whereas large, lightweight packages are charged by dimensional weight. In practice, most consumer packages are charged by dimensional weight.

Optimizing the dimensional weight of your package will help reduce your shipping costs. But why did we use the word “optimize” instead of “reduce”? There are two main reasons. First, downsizing your package too much may result in being charged by its gross weight, which could keep the shipping cost the same or increase it. Second, your goal isn’t to make the package as small as possible. Your goal is to strike a balance between reducing shipping costs and protecting the contents of the package from damage during transit.

To figure out how to optimize the DIM weight of your package, first weigh your package to determine its gross weight. Then, calculate its dimensional weight. Dimensional weight is calculated by multiplying the package’s length, width, and height, then dividing the result by the volumetric divisor. Different carriers use different volumetric divisors, so your package’s dimensional weight will differ depending on the carrier, for example, if shipped by USPS versus FedEx.

Now compare your package’s gross and volumetric weights. If the gross weight is greater than the dimensional weight, there is no need to optimize the dimensional weight because you will be charged based on the gross weight. However, if the dimensional weight is higher, you should consider ways to downsize your package.

First, consider reducing the size of the items in your package. Of course, this is not possible for all items, but it is an option for some. For instance, non-delicate clothes will take up less space if folded properly or vacuum-sealed.

Next, rethink the packaging. For soft or non-fragile items, consider using padded envelopes or poly mailers instead of boxes, as this can significantly reduce shipping costs. If shipping items without a box is not an option, it is important to choose the right size box both to optimize dimensional weight and keep items safe.

The shipping box should be slightly larger than the contents of the package, leaving just enough space for cushioning materials. Too much space will increase dimensional weight while reducing protection. However, no space at all is not an option for most items because they need cushioning to stay safe. The optimal distance between items and the outer box depends on the items’ fragility. It should be about an inch on all sides for non-fragile items, about two inches for moderately fragile items, and about three to four inches for highly fragile or heavy items.

You may not need a new box if yours is too large because some boxes are multi-depth and can be folded or cut down to fit the height of your items. However, if you’re using a regular box that is too large and cannot be cut down, it’s better to replace it with a smaller, appropriately sized box than to overpay for shipping.

Optimizing the dimensional weight of your package essentially boils down to choosing the right type and size of packaging for your items. Proper packaging helps reduce shipping costs and provides adequate protection for the items inside. It’s less about making your package as small as possible and more about striking the right balance between size and protection.