Calculating Dim Weight

Calculating dimensional weight is simple, once you know the methodology. The first step to accurately calculate dimensional weight is to measure the length, width and height of the item you are shipping.

If the item is a small box, this could be easily done with a measuring tape or ruler. A box would be considered a cubed shape. If you are shipping poly bags, tubes or shrink-wrapped items, you still need to find its cubed dimensions.

This is where calculating dimensional weight can get a little tricky. Manually measuring an invisible cubed shape around your object is likely to have a certain degree of inaccuracy. To help with tricky irregulars, a dimensioner can use imaging technology and sensors to create that invisible cubed shape around an object, and capture those dimensions accurately.

The Calculation

Once you have the length, width and height, you’re ready to use the calculate dimensional weight using the dimensional weight formula. To calculate dim weight, multiply the object’s length, width and height in inches. Then, divide that number by 139. The number that results is the package’s dimensional weight in pounds.

The Shipment

After calculating dimensional weight, you now have to determine if the object's dimensional weight or actual weight is greater. The shipping carrier will charge you based on the greater of the two, so you need to make sure you are also taking a weight reading to compare. If the dimensional weight is greater, use that number to compare your available shipping rates. If the actual weight is greater, you need to use that number to rate shop.

Ask Questions

If you’re ever unsure how to calculate dimensional weight or if you are struggling to meet shipping guidelines, ask the person who knows best when it comes to your outbound freight—your carrier! Have a conversation with your carriers about the information you need to provide for dimensional weighing guidelines and what is needed to dispute a back charge due to dimensional weight. If you can prove the dimensions of your package from a dimensioning system’s images, that’s more information to help correct any fees or mistakes on your bill.