Questions
How the calculators work, which rules they follow, and where they stop.
Questions
Which freight class rules do these use?
The 13-subprovision NMFC density scale that took effect on 19 July 2025, which replaced the earlier 11-sub scale. The change split the old top band, everything at 30 pcf and over at class 60, into three: class 60, 55 and 50.
Will this give me the exact class my carrier bills?
For commodities priced on density, it gives the density band and the class that follows. It cannot know whether your item carries a fixed class in the NMFC for handling, stowability or liability reasons. The item's own NMFC listing is the authority, and your carrier or broker can look it up.
Why does my carrier's number differ from mine?
Usually the measurements. Carriers run shipments through dimensioners that record the outside of the load, count overhang and round up, so a pallet you measured at 48 by 40 can be recorded larger. Measure the load as it will ship and round every dimension up.
Which DIM divisor should I use?
139 for FedEx and for UPS daily rates, 166 at UPS retail. If you have a negotiated rate agreement, it will state yours, and a better divisor is often worth more than a discount on the rate itself.
Do these include surcharges?
No. They give the billable weight, the freight class or the chargeable weight, which is the figure rates are applied to. Fuel, zone, residential delivery, additional handling, oversize and accessorial charges all sit on top and come from your rate agreement.
Where do the air and ocean conventions come from?
Air volumetric weight uses the IATA divisor of 6,000 cubic centimetres per kilogram, which makes one cubic metre 166.67 kg. Ocean LCL uses the revenue ton, the greater of cubic metres and metric tons. Some express services use 5,000 instead of 6,000; check with your forwarder.
Is the information free to use?
Yes. No sign-up, nothing stored, and the calculations run in your browser rather than on a server.