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Shipping DIM Weight Comparison Calculator

Enter a box once and see what UPS, FedEx, USPS, DHL, national posts and freight would each bill it as, side by side, and which penalizes it least.

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
Every service bills the same22 lbBilled 22 lb for 8 lb of actual weight
UPS Ground
22 lb
14 lb over actual weight · DIM weight
FedEx Ground
22 lb
14 lb over actual weight · DIM weight
USPS Ground Advantage
22 lb
14 lb over actual weight · DIM weight
USPS Priority Mail
22 lb
14 lb over actual weight · DIM weight

Cut the height to 4 in or less and UPS 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?

UPS, FedEx and USPS all divide a box's cubic inches by 139 and round each fractional inch up, so above one cubic foot they bill the same weight. Below it, USPS bills actual weight while UPS and FedEx still charge DIM. International express uses 5000 cm³ per kg; air cargo uses a gentler 6000.

Each carrier multiplies the box's sides, divides by its divisor and bills whichever is heavier, the result or the scale weight. UPS, FedEx and USPS round every fractional inch up and bill whole pounds; USPS only does this for parcels over one cubic foot. Kilogram-billed services divide cubic centimetres and round up to the next half kilogram. Oversized parcels also carry a minimum billable weight, 40 lb for Additional Handling and 90 lb for Large Package on UPS and FedEx.

DIM weight = L × W × H ÷ divisor; billable = max(actual, DIM, surcharge minimum)
139
UPS, FedEx and USPS, cubic inches per pound
5000
International express and most posts, cm³ per kg
6000
IATA air cargo and Canada Post Regular Parcel, cm³ per kg
4000
Australia Post, 250 kg per m³
3000
Road freight, 333 kg per m³
1,728 in³
One cubic foot, the USPS threshold
An 18 × 14 × 12 in box weighing 8 lb, by service
ServiceDivisorDIM weightBilled atBills actual weight from
UPS Ground13922 lb22 lb22 lb
FedEx Ground13922 lb22 lb22 lb
USPS Ground Advantage13922 lb22 lb22 lb
UPS Worldwide Express13922 lb22 lb22 lb
DHL Express Worldwide13922 lb22 lb22 lb
Canada Post Regular Parcel6,0008.5 kg8.5 kg8.5 kg
Australia Post Parcel Post4,00012.5 kg12.5 kg12.5 kg
Air freight (IATA)6,0008.5 kg8.5 kg8.5 kg

Worked example

A 12 × 12 × 12 in box weighing 5 lb.

  1. 1UPS Ground: divisor 139, billed at 13 lb (DIM weight)
  2. 2USPS Ground Advantage: divisor 139, billed at 5 lb (actual weight)

USPS Ground Advantage bills it lighter, so it takes the smaller DIM penalty.

Frequently asked questions

Which carrier charges the least dimensional weight?

Inside the US, USPS for boxes of one cubic foot (1,728 in³) or less, which it bills at actual weight while UPS and FedEx apply DIM to every package. Above one cubic foot all three now divide by 139, so the box bills the same weight everywhere and the rate card decides. Internationally, air cargo and Canada Post Regular Parcel use 6000, which bills about 17% lighter than express couriers' 5000.

Did USPS change its dimensional weight divisor?

Yes. From 12 July 2026 USPS divides by 139 instead of 166 and rounds every fractional inch up, matching UPS and FedEx. It raised billable weight by about 19% on parcels over one cubic foot. Parcels of one cubic foot or less still bill at actual weight.

Can I negotiate a better DIM divisor?

Often, if you ship volume. UPS and FedEx contracts commonly raise the divisor to 166, 194 or higher for large accounts, which lowers DIM weight on every package: an 18 × 14 × 12 box drops from 22 lb at 139 to 19 lb at 166. Ask for it alongside rate discounts, and check that the new divisor applies to all services you use.

Why did my DIM weight go up without the box changing?

Probably the rounding rule. Since 18 August 2025 UPS and FedEx round every fractional inch up, and USPS followed on 12 July 2026. An 11.1 × 8.5 × 6.2 in box is billed as 12 × 9 × 7, which takes it from 5 lb to 6 lb. Measure boxes to the nearest tenth and pick sizes that are whole inches when packed.

What are the 40 lb and 90 lb minimums?

UPS and FedEx bill oversized parcels at a minimum weight on top of the surcharge. A package longer than 48 in, with a second side over 30 in, more than 105 in in length plus girth or over 10,368 in³ gets Additional Handling and at least 40 lb. One over 130 in length plus girth, 96 in long or 17,280 in³ is a Large Package, billed at least 90 lb.

Which box sizes bill lighter with USPS than UPS or FedEx?

Any box of one cubic foot (1,728 in³) or less after rounding up, such as 12 × 12 × 12, 14 × 12 × 10 or 16 × 12 × 9. USPS bills those at actual weight, while UPS and FedEx charge DIM. A 12 × 12 × 12 box of 5 lb bills 5 lb by USPS and 13 lb by UPS or FedEx.

Sources

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