Making sense of parcel dims

Parcel dimensional weight defined

Since 2010, parcel carriers have taken dimensional weight into consideration when charging shippers.  Lightweight packages can take up a lot of space on their trucks, and in the freight world, space is expensive.  Dimensional weight helps carriers to protect their profit margins. Packages are assessed at either actual weight or dimensional weight and shippers are charged based on the higher number. It is important to note that the carriers can change the divisor when they issue their general rate increases and this can adversely affect your overall shipping spend.

If your products are heavy and take up less space, dimensional weight won’t typically have an impact on your shipping budget, but may come into play from time to time.


Dimensional weight is calculated by taking Length x Width x Height, dividing that by 139 [as of April 2019 ] and rounding up to the nearest whole number.



12” x 12” x 12” box weighing 5 lbs

12 x 12 x 12 / 139=12.4

Therefore, this package would be charged at a 13 lb rate.

It is also important to watch for over length and weight package shipments.  FedEx and UPS will only accept packages up to 150 lbs, up to 165 inches in length and girth combined, and up to 108” in overall length.

What Shippers Can Do

So, knowing all this, what can you as a shipper do to manage parcel shipping costs?

  • Use the smallest box possible (don’t ship packages full of air)

  • Compress goods if possible

  • Use a minimal amount of packing materials

  • Calculate the dim weight before you ship so you can charge your customer the actual rate you will expect to get charged

  • Use reinforced packaging. It is important to note that if your box is crushed you will be charged at the longest point; a bulge in a package can add to your total cost

  • Be aware that if you are shipping in a bag, the dim could change when it goes through the scanners

As the small parcel shipping environment continues to change, more packages than ever are going through these networks due to eCommerce. You will need to be diligent to ensure you do your best to keep costs in line.

Dim factor is just one of the many intricacies involved in parcel shipping. Our experts would be happy to help you with any questions or challenges you’re facing in your business.