Dimensional Weight

The dimen­sion­al weight is the num­ber you get what you take a pack­age’s dimen­sions and mul­ti­ply (length * width * height) and divide that num­ber by 139.

This for­mu­la is a way for FedEx and UPS to cal­cu­late what they con­sid­er a ‘rea­son­able’ weight for the size box. This is impor­tant for the car­ri­ers since they bill based on the weight of the ship­ment. For most ship­ments, the dimen­sion­al weight is used when it is greater than the actu­al weight. The DIM divi­sor of 139 can de negotiated.