The U.S. Postal Service plans to make two changes to how it calculates the size — and, consequently, pricing — of large, lightweight packages on July 12, an effort that would more closely align the agency with FedEx and UPS' practices.
For one planned change, the Postal Service will begin rounding up all fractional measurements of package dimensions to the next whole inch, according to a May 11 notice. "For example, a measurement of 12.2 inches will be calculated as 13 inches," the agency said.
The move mirrors how UPS and FedEx began rounding up fractions of an inch last year, which experts said would result in costlier dimension-based pricing for a wider range of packages, adding to ongoing pricing pressures for shippers.
The Postal Service also plans to adjust how dimensional weight is calculated for package shipping services, using 139 as the divisor instead of 166.
Dimensional weight is calculated by multiplying length, width and height, and dividing the total by a specific number called the divisor. FedEx's divisor is typically 139, while UPS' divisor is 139 for daily rates and 166 for retail rates.
The Postal Service said its divisor change would align prices with the amount of space a package occupies.
The move will also increase costs for lightweight but bulky packages shipped via USPS, per a LinkedIn post from logistics data platform Loop, as the lower divisor means dimensional weight billing will apply to more of those shipments regardless of their actual weight.
"Shippers should review their USPS volume profile and packaging configurations to understand exposure ahead of July 12," according to Loop.
The USPS changes will impact Ground Advantage, Parcel Select, Priority Mail and Priority Mail Express packages that exceed 1 cubic foot and are thus subject to dimensional weight pricing.
"These adjustments allow USPS to continue providing reliable, nationwide service while managing the capacity of our ground and air networks efficiently," the Postal Service said. "By aligning our calculation methods with those used across the shipping industry, we will provide a more consistent experience for businesses and consumers alike."
The changes are set to take effect the same day the Postal Service aims to expand its dimensional reporting requirements. The agency also plans to eliminate ounce-based rate differences for USPS Ground Advantage Commercial shipments on July 12.
