Free Tool
LTL Freight Class Calculator
Enter your shipment dimensions and weight to calculate density and NMFC freight class. Understand what class your freight should be before your carrier decides for you.
How to use: Enter your shipment dimensions (length, width, height in inches) and total weight in pounds. The calculator returns your density in PCF and the corresponding NMFC freight class.
How freight class is calculated
LTL freight class is a standardized pricing category established by the National Motor Freight Traffic Association (NMFTA). Classes run from 50 to 500. Lower numbers mean denser, easier-to-handle freight and lower rates. Higher numbers mean lighter, bulkier, or more fragile freight and higher rates.
The density-based formula is straightforward. Multiply the length, width, and height of your shipment in inches, then divide by 1,728 to convert to cubic feet. Divide the total weight by cubic feet to get PCF (pounds per cubic foot). That PCF number maps to a freight class.
One important caveat: NMFC commodity codes can override density for certain freight types. A carrier may assign a specific class based on what the commodity is, regardless of its density. Always verify the correct NMFC code for your commodity before quoting.
Freight class density reference table
Why freight class causes billing surprises
The freight class system was designed for a paper-based era of freight pricing. Carriers assign a class at booking, but the actual freight class can be overridden during or after delivery through a process called reclassification.
If the carrier measures your shipment at the terminal and finds different dimensions, a heavier weight, or decides the commodity falls under a different NMFC code, they can issue a back-billing charge after delivery. That charge applies the new class to your rate, and it can be significantly higher than what you originally quoted.
For shippers with high freight volumes or irregular shipment profiles, reclassification charges are one of the most common sources of carrier invoice disputes. Using a freight class calculator helps reduce exposure, but it does not eliminate the risk entirely as long as freight class is part of the pricing equation.
Warp does not use freight class
Warp prices by pallet. You tell us how many pallets, where they are going, and when they need to move. The rate is based on that. No freight class lookup, no NMFC code, no density calculation required at booking.
Because Warp prices by pallet, there is no mechanism for a reclassification charge after delivery. The rate you get at booking reflects what you actually pay.
That difference matters most for shippers moving freight that is hard to classify accurately at booking, shipments where dimensions or weight vary across loads, or operations where back-billing creates accounts payable complexity.
See how Warp handles LTL freight and store replenishment without the freight class system.
Freight class FAQ
How is freight class calculated?
Freight class is primarily determined by density, measured in pounds per cubic foot (PCF). Divide the total weight by the cubic footage of the shipment. Higher density means lower (cheaper) class. Classes range from 50 to 500. NMFC commodity codes can override the density-based class for certain goods.
What is PCF in freight?
PCF stands for pounds per cubic foot. It is the density measure used to determine LTL freight class. To calculate it: multiply length x width x height (in inches) to get cubic inches, divide by 1,728 to convert to cubic feet, then divide the shipment weight (lbs) by cubic feet.
What freight class is cheapest to ship?
Class 50 is the cheapest LTL freight class and applies to the densest, most stackable freight at 50 PCF or higher. Examples include heavy machinery parts, metal castings, and dense building materials. Class 500 is the most expensive and applies to very light, low-density freight like ping pong balls.
Can a carrier reclassify my freight?
Yes. LTL carriers inspect freight at the terminal and can reclassify if actual dimensions or weight differ from what was quoted, or if the commodity falls under a specific NMFC code that overrides density-based classification. Reclassification triggers a back-billing charge that can significantly increase the final invoice.
Does Warp use freight class for pricing?
No. Warp does not use freight class, NMFC codes, or density calculations. Warp prices by pallet, so you know what you're paying before the shipment moves. There are no reclassification surprises.
Ship without the freight class guesswork
Warp quotes by pallet. No density math, no NMFC lookup, no reclassification risk after delivery. Share a shipment profile and see what per-pallet pricing looks like for your lanes.