UPS and FedEx dimensional weight history: divisors and rule changes, 2007 to 2026
The short version
- The domestic divisor has fallen twice: from 194 to 166 on January 3, 2011, and from 166 to 139 in 2017. A lower divisor produces a higher dimensional weight from the same box.
- The scope change mattered as much as either divisor change. Until the end of 2014, a Ground package below three cubic feet was billed on actual weight however light it was.
- FedEx applied 139 to US domestic Express and Ground packages subject to standard dimensional pricing on January 2, 2017. UPS applied it to Daily Rates packages over one cubic foot on January 8, 2017 and to the rest on December 24, 2017. UPS Retail Rates still use 166.
- Since August 18, 2025, FedEx and UPS round each dimension up to the next whole inch before calculating, which can add a pound without the divisor moving.
- The divisor is negotiable. An agreement can set a higher divisor, or a size below which dimensional weight does not apply, and the invoice data shows whether either was honored.
UPS and FedEx have changed dimensional weight in two different ways since 2007: which packages it applies to, and the divisor it is calculated with. In 2007 both carriers applied dimensional weight at Ground only to packages of three cubic feet (5,184 cubic inches) or larger, with a divisor of 194. On January 3, 2011 both moved the domestic divisor to 166, still with the three cubic foot threshold at Ground. UPS from December 29, 2014 and FedEx from January 1, 2015 applied dimensional weight to every Ground package regardless of size. FedEx moved its US domestic Express and Ground divisor to 139 on January 2, 2017. UPS did the same in two steps: 139 for Daily Rates packages over one cubic foot from January 8, 2017, and for packages of one cubic foot or less from December 24, 2017. Since August 18, 2025, both carriers have also rounded each fractional dimension up to the next whole inch. The result is that a 6 lb box measuring 18 by 14 by 12 inches, billed at its actual weight at Ground in 2010, is billed at 22 lb today.
Two kinds of change: scope and divisor
Dimensional weight is length times width times height, divided by a divisor, and the carrier bills the greater of that and the actual weight. For the formula, the rounding rules and a calculator, see dimensional weight explained; this page is the history of how the rules got there.
Two different levers have moved over that history, and it helps to keep them apart. A scope change decides which packages dimensional weight applies to at all: every air package, Ground packages at or above a size threshold, or every package in a service. A divisor change decides how heavily it bites on the packages it applies to. Lowering the divisor from 166 to 139 raises the calculated dimensional weight of every box in scope by about 19% before rounding. Removing the three cubic foot threshold brought most Ground packages into scope for the first time, which for light, bulky goods was the bigger change.
UPS and FedEx dimensional weight timeline
Each change with the date it took effect, the services it covered, and what changed. Each row links to the announcement or to a report published before the change took effect.
| Effective | Carrier | Services | Divisor | Scope |
|---|---|---|---|---|
| In force in 2007 | UPS and FedEx | Ground | 194 | Ground packages of 5,184 cubic inches (three cubic feet) or larger. Smaller Ground packages billed on actual weight. |
| January 3, 2011 | FedEx | US domestic Express and Ground | 194 to 166 | Unchanged: Ground still exempt below three cubic feet. |
| January 3, 2011 | UPS | US domestic air and Ground | 194 to 166 | Air at every size; Ground still only at three cubic feet or larger. Exports 166 to 139. |
| December 29, 2014 | UPS | All UPS Ground services and UPS Standard to Canada | 166 | Every Ground package, regardless of size. Announced June 17, 2014. |
| January 1, 2015 | FedEx | FedEx Ground and Home Delivery | 166 | Every Ground package, regardless of size. Announced May 2, 2014. |
| January 2, 2017 | FedEx | US domestic Express and Ground | 166 to 139 | Express and Ground packages subject to standard dimensional pricing. Economy services and negotiated divisors are separate. Announced September 19, 2016. |
| January 8, 2017 | UPS | US domestic services on Daily Rates | 166 to 139 | Packages over one cubic foot (1,728 cubic inches). Smaller packages stayed at 166. |
| December 24, 2017 | UPS | US domestic services on Daily Rates | 166 to 139 | Packages of one cubic foot or less, so 139 now applied to every Daily Rates package. |
| January 22, 2018 | FedEx | FedEx SmartPost, now Ground Economy | Dimensional pricing applied | The economy service brought into dimensional pricing. Announced September 18, 2017. |
| August 18, 2025 | FedEx and UPS | Domestic package services | Unchanged at 139 | Each fractional dimension rounded up to the next whole inch before calculating. Our coverage: FedEx, UPS. |
Sources, by row: the 2007 baseline and the FedEx 2011 change from DC Velocity’s reports of May 4 and May 11, 2014; UPS 2011 from UPS’s rate announcement as reprinted by PARCEL on November 1, 2010; UPS 2014 from UPS’s release of June 17, 2014; FedEx 2015, 2017 and 2018 from the FedEx newsroom releases of May 2, 2014, September 19, 2016 and September 18, 2017; both UPS 2017 changes from DC Velocity’s reports of November 20, 2016 and October 25, 2017, with 139 on every Daily Rates package as shown in the current UPS Rate and Service Guide. UPS Retail Rates remain at 166 throughout.
Read down the table and the pattern is the same each time: FedEx announces, UPS follows within months, and the two end up on the same rule. The one sustained difference was 2017, when for almost a year UPS kept 166 for Daily Rates packages of one cubic foot or less while FedEx charged 139 on all its standard Express and Ground packages. UPS closed that gap at its next rate change. Economy services followed their own timetable, as the SmartPost row shows.
What each change did to the same box
Illustration using 2026 FedEx Ground prices, not historical shipping prices. Two boxes, billed under the rule in force in each period. To isolate the rule from the rate increases in between, every row uses the same price list: FedEx Ground 2026 list rates, zone 5. The UPS row applies UPS’s 2017 rule to that same FedEx price table, solely to show its effect on billable weight. The large box is 18 by 14 by 12 inches (3,024 cubic inches, below three cubic feet) with 6 lb inside it. The small box is 12 by 10 by 8 inches (960 cubic inches, under one cubic foot) with 3 lb inside.
| Rule in force | Large box billed | At 2026 FedEx zone 5 | Small box billed | At 2026 FedEx zone 5 |
|---|---|---|---|---|
| Ground before December 29, 2014 (no DIM below three cubic feet) | 6 lb (actual) | $18.60 | 3 lb (actual) | $16.81 |
| Divisor 166 on every Ground package (2015 to 2016) | 19 lb | $26.42 | 6 lb | $18.60 |
| UPS rule, January 8 to December 23, 2017 (139 over one cubic foot, 166 below), on the same FedEx prices | 22 lb | $28.28 | 6 lb | $18.60 |
| Divisor 139 on every standard Ground package (FedEx from January 2, 2017; UPS from December 24, 2017) | 22 lb | $28.28 | 7 lb | $19.19 |
Dimensional weight rounded up to the next whole pound: 3,024 ÷ 166 = 18.2, billed 19 lb; 3,024 ÷ 139 = 21.8, billed 22 lb; 960 ÷ 166 = 5.8, billed 6 lb; 960 ÷ 139 = 6.9, billed 7 lb. Prices from the FedEx Standard List Rates effective January 5, 2026, before fuel and surcharges, and used for every row so that only the rule changes. These are not the prices charged in those years.
The large box costs 52% more under today’s rule than under the rule before 2015, at the same rates, with nothing inside it changed. Most of that came from the scope change: bringing the box into dimensional pricing at 166 took it from 6 lb to 19 lb. The 2017 divisor added three more pounds. The small box moved less, 14% across the period, because a 960 cubic inch box does not generate much dimensional weight at any divisor.
What the 2025 rounding change does
The boxes above have whole-inch dimensions, so the August 18, 2025 change does not touch them. A real carton rarely measures to the whole inch. Before that date, FedEx and UPS rounded a fraction under half an inch down; since then, both round every fraction up to the next whole inch. The same carton at the same 139 divisor:
| Measured carton | Dimensions used | Dimensional weight |
|---|---|---|
| 12.1 × 10.1 × 8.1 inches, rounding before August 18, 2025 | 12 × 10 × 8 (960 cubic inches) | 7 lb |
| Same carton, every fraction rounded up | 13 × 11 × 9 (1,287 cubic inches) | 10 lb |
960 ÷ 139 = 6.9, billed 7 lb; 1,287 ÷ 139 = 9.3, billed 10 lb. Rounding rules from Supply Chain Dive’s reports of the FedEx and UPS announcements.
A tenth of an inch on each side added 3 lb of dimensional weight with no change to the divisor. That is why carton specifications matter: a box designed a fraction under the whole inch, rather than a fraction over, keeps the dimensions the carrier bills on. See dimensional weight explained for how to specify around it.
Why 139 and 166?
The divisors roughly correspond to metric volumetric factors. A divisor of 139 cubic inches per pound is very close to 5,000 cubic centimeters per kilogram, the factor used for international express shipments; 166 is close to 6,000 cubic centimeters per kilogram. When FedEx moved domestic shipments to 139 in 2017, it brought them onto the divisor its international express services already used, and UPS followed. UPS kept 166 for Retail Rates, the prices a walk-in or occasional shipper pays, which is why both divisors still appear in UPS’s published rules.
How a lower divisor raises shipping costs
The divisor sits underneath the dimensional weight calculation, so lowering it raises the calculated dimensional weight of every package in scope by the same proportion before rounding: 166 ÷ 139 = 1.19, or about 19% more. Billable weight may not change at all. That does not mean a 19% price increase. The billed weight only rises for packages whose dimensional weight already exceeded, or now exceeds, their actual weight, and rates do not rise in proportion to weight. In the example above the large box’s billed weight rose 16%, from 19 to 22 lb, and its price 7%, from $26.42 to $28.28.
It also changes on a different calendar from the rates. A divisor change arrives with an annual rate announcement but is not part of the announced average increase, so a shipper whose freight is light and bulky can see a far larger increase than the headline figure in the year a divisor moves. Our rate increase history covers the headline figures.
Can businesses negotiate a higher dimensional weight divisor?
Yes. The published divisor is the default, and an agreement can override it. The terms we see take two forms: a higher divisor, such as 166 or above, applied to some or all services; or a size threshold below which dimensional weight does not apply, which reinstates a version of the pre-2015 rule for the shipper’s own packages. Some agreements do both. Which is worth more depends on the shipper’s cartons: a threshold is worth most to a shipper with many small light boxes, a higher divisor to one with large light boxes. The way to choose is to rerate a year of shipments under each and compare. Our DIM divisor calculator shows the difference for a single box.
Two things to watch. A divisor concession often names specific services, so Ground may carry the negotiated divisor while Express or an economy service stays at 139. And a concession is only worth what the billing applies.
How to check whether your carrier used the contracted divisor
The invoice data carries what you need. For each package, the detailed invoice file from UPS or FedEx shows the dimensions the carrier recorded, the actual weight and the billed weight. To check it:
- Find the divisor in your agreement, and which services and rate types it applies to.
- For each package, round each recorded dimension up to the next whole inch, multiply them, divide by the contracted divisor and round up to the next pound.
- Compare the greater of that figure and the actual weight, rounded up to the next pound, with the billed weight. A billed weight above it flags a discrepancy to investigate, not yet an overcharge.
- Before calling it one, rule out the other explanations: a minimum billable weight that applies with an additional handling or oversize surcharge, recorded dimensions that differ from yours, or a rule specific to the service. If the billed weight matches 139 and none of those apply, the contracted divisor was not used.
- Apply the rules in force on each shipment date. A shipment before August 18, 2025 was measured under the earlier rounding rule, so rerating it with today’s rule would overstate what it should have cost.
- Check the recorded dimensions against what you shipped. A carrier’s measurement that is larger than the carton is a separate error, and one that recurs on the same carton is worth raising.
Doing that by hand works for a sample. Across a year of invoices it is a job for software, which is part of what our parcel audit does each week, and our invoice audit guide covers the rest of the checks.
Frequently asked questions
When did UPS and FedEx start applying dimensional weight to Ground packages?
Before 2015, both carriers applied dimensional weight at Ground only to packages of three cubic feet (5,184 cubic inches) or larger, and that threshold was in force in 2007. UPS applied it to every Ground package from December 29, 2014, and FedEx to every FedEx Ground and Home Delivery package from January 1, 2015.
When did FedEx change its dimensional divisor from 166 to 139?
January 2, 2017, for US domestic FedEx Express and FedEx Ground shipments. FedEx announced the change on September 19, 2016. The previous change, from 194 to 166, took effect January 3, 2011.
What was the UPS dimensional weight divisor in 2017?
It depended on the date and the package. From January 8, 2017, UPS Daily Rates packages over one cubic foot used 139 and packages of one cubic foot or less used 166. From December 24, 2017, 139 applied to every Daily Rates package. UPS Retail Rates used 166 throughout.
Why does UPS use 139 or 166?
139 applies to UPS Daily Rates, the published rates for account holders, and 166 to UPS Retail Rates, the prices for shipping at a counter without an account. A UPS agreement can set a different divisor for the account’s own shipments.
How does a lower DIM divisor increase shipping costs?
Dimensional weight is the package’s volume divided by the divisor, so a smaller divisor gives a larger calculated dimensional weight from the same box: moving from 166 to 139 raises it by about 19% before rounding. The billable weight, and the cost, rise wherever the dimensional weight is higher than the actual weight, which is most often light, bulky packages.
Can businesses negotiate a higher dimensional weight divisor?
Yes. An agreement can set a higher divisor, a size threshold below which dimensional weight does not apply, or both, and can limit either to certain services. The value depends on the shipper’s cartons, which is why it is worth rerating your own shipments before asking.
How do I check whether my carrier used the contracted divisor?
Take the recorded dimensions from the invoice data, round them under the rule in force on the shipment date (every fraction up since August 18, 2025), divide their product by your contracted divisor and round up to the next pound. A billed weight higher than the greater of that and the rounded actual weight flags a discrepancy to investigate. Check the contracted divisor and the services it covers, the measurement record, and any minimum billable weight that comes with a surcharge before treating it as an overcharge.
Sources
- FedEx newsroom: FedEx Announces Pricing Changes, May 2, 2014; FedEx to Increase Shipping Rates for Express, Ground and Freight Services, September 19, 2016; Shipping Rates to Increase for FedEx Express, FedEx Ground and FedEx Freight Services, September 18, 2017.
- UPS: UPS Announces Dimensional Weight Changes, June 17, 2014; the 2011 rate announcement from rates.ups.com, as reprinted in UPS Rates to Increase in 2011, PARCEL, November 1, 2010; and the 2026 UPS Rate and Service Guide for the current Daily and Retail divisors.
- DC Velocity, Mark B. Solomon: FedEx to shift to dimensional pricing on many ground parcel shipments Jan. 1, May 4, 2014; “Tough love” or power grab?, May 11, 2014; UPS, following FedEx lead, shrinks threshold of dimensional pricing on parcel shipments, November 20, 2016; UPS to hike tariff rates 4.9 percent, shrink dimensional price divisor on 1-cubic-foot parcels, October 25, 2017.
- Supply Chain Dive: FedEx plans dimensional weight tweaks that could impact pricing and UPS matches FedEx with dimensional weight change, 2025, for the rounding rules before and after August 18, 2025.
- FedEx Standard List Rates, effective January 5, 2026, for the worked example.
- ebb Logistics coverage of the August 18, 2025 rounding change at FedEx and UPS.