Dimensional weight calculator: air freight and parcel
Carriers bill the greater of two weights — actual or dimensional. Enter the size and weight of your pieces: the calculator runs both the air freight divisor of 166 and the ground parcel divisor of 139, and tells you which weight you will pay for. Inches and pounds. Everything runs in your browser — nothing is sent anywhere.
Got your chargeable weight — now get a rate. The team (your company could be here) will find the flight or service and price it for your lane.
Get a shipping quotethis button is for saleHow dimensional weight works
The formula is the same everywhere, only the divisor changes: dimensional weight (lb) = length × width × height (in) ÷ divisor. A divisor of 166 means one cubic foot counts as about 10 pounds. If the actual scale weight is higher, you pay actual; if the freight is light and bulky, you pay dimensional. It keeps a pallet of pillows from shipping at the price of a pallet of bolts.
Which divisor applies
166 — air freight
The international air standard, and what forwarders quote for airport-to-airport moves. It is the same rule as the IATA metric divisor of 6000, just written in inches and pounds: 6000 cubic centimetres per kilogram works out to 166 cubic inches per pound.
139 — FedEx and UPS
Both carriers use 139 for domestic ground and air parcels. The lower divisor means a bigger dimensional weight for the same box: that 48×40×48 pallet is 555 pounds at 166 and 663 pounds at 139. Retail rates and some account agreements may use a different number, so check your contract before you quote a customer.
What your own contract says
Negotiated accounts sometimes carry 150, 194 or another divisor, and LTL carriers apply a different system entirely — freight class based on pounds per cubic foot. If your rate sheet names a divisor, use that one.
Reference numbers
| Divisor | Used for | One cubic foot counts as |
|---|---|---|
| 166 | Air freight, international | ≈ 10 lb |
| 139 | FedEx and UPS parcel | ≈ 12 lb |
| 194 | Some LTL dimensional programs | ≈ 9 lb |
| 6000 (metric) | Same as 166, in cm and kg | 1 m³ ≈ 167 kg |
Measure the piece as it ships — packaged, palletized, to the outermost points including any overhang. Carriers dimension what arrives on their dock, not the bare product.
FAQ
Which weight do I actually pay?
The greater of the two. Compare actual scale weight against dimensional weight and the carrier bills whichever is higher. That is the chargeable weight.
Why is my parcel quote higher than my air quote?
Because 139 is a smaller divisor than 166, and a smaller divisor makes a bigger number. The same box that is 555 pounds on an air waybill is 663 pounds as a parcel.
Do I round the dimensions?
Most carriers round each dimension up to the next whole inch before multiplying, then round the result up to the next whole pound. The calculator does not round the inputs, so your carrier's figure may land a pound or two higher.
Does this work for LTL freight?
Not really. LTL is priced by freight class, which comes from density — pounds per cubic foot — rather than a dimensional divisor. Use our freight volume calculator to get cubic feet, then divide your weight by it.
Is my shipment data sent anywhere?
No. The widget is a script running entirely in your browser — dimensions and results are never transmitted or stored.