Having successfully navigated the holiday peak shipping season, UPS and FedEx will next roll out a change to their pricing model.

Starting Monday, UPS will no longer charge for U.S. ground packages under 3 cubic feet by weight but by their “dimensional weight.”
Memphis-based FedEx will roll out the same change on Jan 5.
Instead of simply weighing a box, retailers must multiply its length by its height and width, and then divide that by 166 to reach its dimensional weight.
“We believe this (dimensional weight pricing) will encourage customers to reduce their package sizes,” Bill Smith, UPS vice president of marketing, told Reuters.