Methodology
This page describes exactly how a number on this site is produced, so that you can check it against the primary source rather than take it on trust. It also states plainly what this site is not, because a reference is only useful if you know the limits of the thing you are citing.
What we are not
Densio is not a freight broker, carrier, or 3PL. We do not sell freight services and we do not earn a commission from any carrier named on this site.
No one at Densio is a licensed customs broker, a certified transportation professional, or a practising classification specialist. We have no industry tenure to claim, and we do not claim any.
We are not affiliated with, endorsed by, or in partnership with NMFTA or any carrier. Sources are cited because they are the authority on the data, not because there is a relationship.
The value we can offer is a documented method and an auditable record, not authority. If you need a binding classification decision, ask your carrier.
The calculation, step by step
Convert each dimension to feet: inches are divided by 12, centimetres by 30.48. Units are never silently converted — the unit you choose is the unit used.
Multiply the three converted dimensions to get volume in cubic feet.
Divide weight in pounds by volume in cubic feet to get density in pounds per cubic foot.
Find the single subprovision whose interval contains that density, and report its class. The intervals are half-open, so a value equal to a lower bound belongs to that band.
Precision, and why it is stated
Classification uses the full-precision result of the arithmetic above. Nothing is rounded before the band lookup. This matters because a shipment can sit a fraction of a percent away from a boundary, and rounding first can move it into the wrong band.
Only the displayed figures are rounded, to two decimal places. The same input therefore always produces the same class, whether the calculation runs in your browser or on our server.
Dates on this site
"Data source verified" is a single date shared by every page that uses a given data file. It is the date we last checked the data against the primary source, and it is stored in the data file rather than generated when a page renders.
"Page reviewed" appears only on pages a person has actually read through after the last change. Most pages here are generated from shared data and will not carry it. A generated page claiming individual review would be a false statement, so the template cannot produce one.
Corrections
If something here is wrong, we want the specific error. Write to [email protected] with the page and the figure you believe is incorrect, and if you can, the source that contradicts it.
Corrections to the underlying scale take priority over everything else on the site, because a wrong class value would make every page that uses it wrong at once.
Frequently asked
Are you a freight professional?
No. Densio is not staffed by practising freight professionals, and this page says so deliberately. The method and the sources are documented so that you can verify the output without relying on our credentials.
Why publish a methodology page at all?
Because a calculator that only shows a number asks to be trusted. A calculator that shows the arithmetic and the source can be checked. We would rather be checkable.
How often is the underlying data checked?
NMFTA publishes new dockets on an ongoing basis, and Docket 2025-1 was described by NMFTA as the first phase of a larger overhaul. We therefore treat the scale as something that will change, and we keep the version and the verification date attached to every figure derived from it.
Data source verified:
Primary source: NMFTA Disposition Bulletin 1371 — density and class breaks for the 13-subprovision structure
Archived copy: snapshot 0, snapshot 1