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USPS Dimensional Weight Calculator

USPS billable weight under the July 2026 rules: 139 instead of 166, fractional inches rounded up, and no DIM on parcels of one cubic foot or less.

Updated · By Niraj Kumar · 8 sources

Box

Measured inMeasured in
in
in
in

Measure the packed box at its widest points, bulges included. UPS, FedEx and USPS round every fractional inch up.

lb

Parcels are rated box by box; freight on the whole shipment.

Compare

ServicesServices
Billable weight on USPS Ground22 lbBilled on dim weight
Dimensional weight
22 lb
18 × 14 × 12 in ÷ 139
Actual weight
8 lb
Rounded up to the billing step
Billed over actual weight
14 lb
175% more than the scale says
Rank
3rd lightest of 4
US parcel

Cut the height to 6 in or less and USPS Ground bills actual weight.

Chargeable weight for this shipment, in lb, lightest firstHover or focus a row for the DIM and actual weight behind it. Services billed in the other unit are converted.
  1. 1UPS Ground÷ 13922 lb
  2. 2FedEx Ground÷ 13922 lb
  3. 3USPS Ground Advantage÷ 13922 lb
  4. 4USPS Priority Mail÷ 13922 lb
Service by service, in each one's billing unit
ServiceDivisorDIM weightActualBillable, shipmentBilled on
UPS Ground13922 lb8 lb22 lbDIM weight
FedEx Ground13922 lb8 lb22 lbDIM weight
USPS Ground Advantage13922 lb8 lb22 lbDIM weight
USPS Priority Mail13922 lb8 lb22 lbDIM weight

How do carriers calculate dimensional weight?

USPS charges dimensional weight only on parcels larger than one cubic foot (1,728 in³). From 12 July 2026 it rounds each side up to the next inch and divides by 139, down from 166. Parcels of one cubic foot or less bill at actual weight, rounded up to the next pound.

DIM weight = L × W × H ÷ divisor; billable = max(actual, DIM, surcharge minimum)

This page uses the same method as the Shipping DIM Weight Comparison Calculator, which explains each term and assumption in full.

USPS Ground Advantage beside the alternatives: a 12 × 12 × 12 in box weighing 5 lb
ServiceDivisorDIM weightBilled atBills actual weight from
UPS Ground13913 lb13 lb13 lb
FedEx Ground13913 lb13 lb13 lb
USPS Ground Advantage13913 lb (exempt)5 lbAny weight
USPS Priority Mail13913 lb (exempt)5 lbAny weight

Worked example

A 12 × 12 × 12 in box weighing 5 lb, shipped via USPS Ground Advantage.

  1. 1Sides as rated: 12 × 12 × 12 in
  2. 2Volume: 1,728 in³
  3. 3DIM weight: 1,728 ÷ 139 = 12.43, rounded up to 13 lb
  4. 4Actual weight: 5 lb
  5. 5DIM does not apply to this box on this service

Billed at 5 lb (actual weight).

Frequently asked questions

When does USPS charge dimensional weight?

Only when the parcel is over 1,728 cubic inches, one cubic foot, measured after rounding each side up to the next inch. That covers Priority Mail, Priority Mail Express, Ground Advantage and Parcel Select. A 12 × 12 × 12 box sits exactly on the line and bills at actual weight; 12 × 12 × 12.2 rounds to 12 × 12 × 13 and does not.

Does USPS charge extra for long or large boxes?

Yes, separately from dimensional weight. Nonstandard fees apply to parcels longer than 22 in, a higher fee above 30 in, and parcels over two cubic feet. The calculator flags each one it triggers.

What dimensional weight divisor does USPS Ground Advantage use in 2026?

USPS Ground Advantage divides in³ by 139 and rounds up to the next whole lb. Each fractional inch is rounded up before multiplying. DIM applies only above 1,728 in³; smaller boxes bill at actual weight.

Sources

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