The division by 5000 when calculating volumetric weight is a common practice used by many international shipping carriers and logistics companies, and it's often referred to as the "dimensional weight factor." The value 5000 is typically used for calculating volumetric weight when the measurements of the package are in centimeters (cm). If measurements are in inches, the dimensional weight factor is often 139 (for domestic shipments in the United States) or 166 (for international shipments in the United States).