About MyFreightClass

MyFreightClass is a free set of calculators for less-than-truckload freight: freight class and density, CBM, dimensional and chargeable weight, linear feet, pallet builds and fuel surcharge. It exists because the arithmetic that decides an LTL invoice is not complicated, but it is easy to get subtly wrong, and being wrong costs money.

Everything runs in your browser. Nothing you type is sent anywhere.

Built on the current NMFC scale

On 19 July 2025 the National Motor Freight Traffic Association restructured freight classification under Docket 2025-1, moving from commodity-based to density-based classification and expanding the density scale from 11 subprovisions to 13. The two new subprovisions introduced classes 55 and 50, which had not previously existed on the density scale — before the change, everything at 30 lb/ft³ or denser landed at class 60.

That matters because a calculator still running the old 11-subprovision table returns a class that is too high for dense freight, and therefore an estimate that is too expensive. The freight class calculator here uses the 13-subprovision scale and names its sources on the page.

Where the numbers come from

Subprovisions 11, 12 and 13 are taken from NMFTA's own published FAQ on the 13-sub structure. Subprovisions 1 through 10 are not published free by NMFTA — they sit behind the ClassIT+ subscription — so they are taken from the 13-tier table published by ArcBest, a national LTL carrier, whose subprovisions 11-13 match NMFTA's primary publication exactly. The 19 July 2025 effective date is corroborated by Old Dominion and Averitt. Each source is linked on the freight class page with the date it was retrieved.

What this site deliberately does not do

It carries no live rate data. DIM divisors, fuel surcharge percentages and carrier rates all differ by carrier and change continuously, so any value hardcoded here would be stale within days and would quietly produce quotes that do not match invoices. Where a current number is needed, the calculator asks you for it and tells you where to read it off.

It also does not quote freight, capture leads or broker shipments. These are calculators.

How the math is checked

Every formula has a regression test whose expected values were worked out independently before the code was written, rather than by running the code and recording what it said. The density boundaries are tested on both sides of every breakpoint, because an off-by-one at a boundary moves the freight class and therefore the price.

Not official guidance

MyFreightClass is independent and not affiliated with NMFTA or any carrier. A density-derived class is a planning estimate; the NMFC item number for your commodity and your carrier's own tariff govern what is actually billed.