Explaining Volumetric Weight for International Shipping
When you ship an item via express carrier that uses a mode of transportation to ship your item to you, you will be charged Volumetric weight (also known as Dimensional weight) or the actual scale weight of the item – whichever is greater.
Think of it like this, your package is renting space on their airplane and if your large rectangular box takes up much more space than that tiny, heavy box sitting next to it, your rent is going to be higher.
Volumetric weight is based on the size of the package: Length x Width x Height, divided by the carrier's Volumetric Factor (5000) = Volumetric Weight
For detailed infomation please see DHL website;