Dimensional (DIM) weight, sometimes referred to as volumetric weight, is a pricing technique used by shipping, freight and transportation companies. It considers the volume of the package being shipped rather than just the weight. The rationale behind this is simple: large packages that are lightweight can take up just as much space on a truck or airplane as a small but heavy package. For example, consider shipping a giant box of feathers versus a small box of lead. Even though the feathers might weigh very little, they would take up a significant amount of space, potentially preventing other goods from being shipped in the same load.
Shipping companies have both weight and space constraints. Large but lightweight packages can quickly fill up transportation containers without contributing much to the overall weight. To ensure they are adequately compensated for the space these packages occupy, shipping carriers consider the dimensional weight when calculating shipping costs.
The formula for dimensional weight can vary depending on the shipping company and the region. However, the general approach is consistent:
Step 1 – Measure the Package: Determine the length, width, and height (LxWxH) of the package.
Step 2 – Calculate the Volume: Multiply the length, width and height together.
Step 3 – Determine the Dimensional Weight: Divide the volume by the specific divisor provided by the shipping company.
Step 4 – Compare Dimensional Weight to Actual Weight: Shipping carriers will charge based on whichever weight is higher – the actual or dimensional weight.
Since DIM weight could impact a package’s shipping costs, it is critical that your measurements are as accurate as possible. Relying on manual measurements and calculation of DIM weight could lead to unnecessary additional shipping costs. Carriers have even started to impose audit fees if shippers misstate package dimensions.
For example, let’s say a package that weighs 18-pounds has a DIM weight of 20-pounds. Due to human error when measuring the package, the DIM weight is recorded as 22-pounds. Since the billed weight is the higher of the two, the carrier will charge based off the inaccurate, 22-pound weight, adding unnecessary costs to the shipment.
When it comes to saving on shipping costs, there are so many aspects out of your control (think inflation or increasing labor and operational costs), focus on what you can control – accurate dimensions for the most cost-effective shipping rates.