NMFC Freight Class Estimator

What Is NMFC Freight Class?

The National Motor Freight Classification (NMFC) is the standardized system US LTL (less-than-truckload) carriers use to price freight. Every commodity is assigned a class from 50 (densest, cheapest per pound) to 500 (lightest, most expensive). The NMFC is maintained by the National Motor Freight Traffic Association (NMFTA), and the official commodity classifications are published in a proprietary directory that carriers license from NMFTA. Class determination is based on four factors: density, stowability, handling characteristics, and liability (risk of damage, theft, or hazmat concerns).

Why Density Matters

Density is by far the most commonly used factor in practice. Carriers want to fill their trailers efficiently; dense freight uses less cubic space per pound of revenue, so they charge less for it. The NMFTA publishes a density-based rating scale that maps pounds-per-cubic-foot to class ranges — this scale is public and widely reproduced. For many commodities, especially "exempt" freight and FAK (freight all kinds) quoting, density is the determinative factor even though the official NMFC rule may technically reference other criteria.

What This Tool Does (and Doesn't)

This tool computes density from your dimensions and weight and maps it onto the public density scale. It does NOT reproduce the NMFC commodity directory — those are proprietary tables that belong to NMFTA, not public-domain data. For commodities whose class is NOT density-based (many chemical, electronic, and handling-sensitive items), the actual class may be higher or lower than the density scale suggests. Use this tool for cube-based budgeting and preliminary rate estimation; confirm the actual class with your carrier or your NMFTA ClassIT subscription before issuing binding bills of lading.

Automating Freight Rating

If you ship LTL regularly, density-based rating should live in your item master — every SKU carries its dimensions, weight, and rated class, and every order line automatically computes total weight, cube, and the correct class for rate shopping and BOL generation. Pair with the Landed Cost Calculator to understand how freight flows into per-unit cost. Learn about integration services, custom reporting, or get in touch.