On a recent carrier contract review with a client, I was trying to explain how their packages were getting shipping charge corrections due to dimensional weight issues. The client responded by explaining how they negotiated their Oversize 2 (OS2) boxes to be charged at 50 lbs, and dimensional weights shouldn’t be an issue. After reading that, I’m sure some readers will checking to make sure they didn’t receive the 2006 spring issue. As shocked as I was to hear “oversize,” dimensional weighing retains its mystery among shippers, despite the fact that it has been more than two years since it went into effect.

Until 2007, dimensional weighing applied to air and international shipments. In 2007, all three major parcel carriers rolled dimensional weight methodology for ground. Although carriers provided examples where dimensional weighing could be more advantageous compared to the old OS1, OS2, OS3 system, all clients I have worked with — especially in the auto parts and clothing industries — experienced a huge increase in transportation costs. Simply put, dimensional weight equals the multiplication of the three dimensions of the box divided by a dimensional factor. For ground packages, there is a threshold of three cubic feet. If the box is smaller than three cubic feet, dimensional weight doesn’t apply. In general, dimensional weight affects low density / high volume shipments. 

A typical shipping operation would have a TMS system recording the scale weight of the package and manifesting it to the carrier. The carrier will charge you at this weight initially; however, they will apply a charge correction if there is any difference between the manifested weight and the weight they measure. If you are charging your recipient based on the cost from your TMS, the charge corrections can result in unaccounted costs for your operation. The best practice is getting the correct dimensional weight and manifesting it to the carrier first so that charge corrections can be avoided. Submitting the box type or dimensions in a reference field will help auditing the dimensions of the package when the invoice is received.
Better Shipping Practices
Simple problems should have simple solutions. The dimensional weight affects the large boxes: so shrink your boxes and you will save money! 
• If you are shipping shrinkable items such as clothing/ pillows / handbags, try vacuum packaging. You will reduce the volume, and the plastic packaging will provide extra protection.
• If you are shipping rigid items that would take less space if they were disassembled, try to save volume by leaving the assembly to the end user. 
• Most merchandise shipped by e-commerce is designed for the retail environment with bigger than necessary surfaces to grab the attention of the shopper. They are not designed to save space during parcel shipping. If possible, choose merchandise that avoids unnecessary packaging.

The shipping boxes should be properly selected depending on the shipment. Void spaces should be kept to a minimum without sacrificing protection.

Another good practice is to get an automated dimension scanner based on the size of your operation. There are many types and brands that measure the dimensions of the box and transmit them to the TMS. This will automate measuring while eliminating user mistakes. 
Better Parcel Contract
Once you optimize your box sizes, the next step is talking to your carrier about incentives in dimensional weight. A higher dimensional factor will bring down your weights. Normally dimensional weight applies to all air packages. You can ask for a threshold (such as one cubic foot) for the air and international packages. That way, dimensional weights will not apply to packages below this threshold. Carriers apply various surcharges to packages over certain sizes such as additional handling charges, large package surcharges and excess limits charges. You can negotiate discounts on these surcharges as well.

Mistakes can happen on the shippers’ or carriers’ end during measuring. Auditing your invoices for dimensional weights can save you from costly mistakes. To help auditing, the box size should be manifested as a reference field so that it will be available in the invoice data. The dimensions from your system can and will differ from the dimensions your carriers measure, largely because of the bulging of the boxes when stacked. Since the carriers round up the dimensions, a slight deformation of the box will result in at least an inch of increase.
If your packages are prone to be affected by dimensional weights, you should take the necessary steps to cut down and control your shipping costs.
Baris Tasdelen is a Transportation Analyst at enVista LLC and can be reached at btasdelen@envistacorp.com