“Dimensional weight” is where UPS and FedEx will estimate the minimum weight of a package based off the size of the box, not off the actual weight of a box. As an example a box of 100 water bottles weighs the same as 1000 pens, but because the of the size of the water bottle box it cost twice as much to ship.
READ MORE IN OUR BLOG ON THIS TOPIC: Shipping bricks or feathers? What is “Dimensional Weight”?