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.
Freight class at a glance
Freight class is the National Motor Freight Traffic Association (NMFTA) density-based pricing system for less-than-truckload shipments. There are 18 classes from 50 to 500. The lower the class, the denser the freight and the lower the per-pound rate. The higher the class, the lighter or bulkier the freight and the more expensive it is to ship. Most freight gets its class from density alone, but specific NMFC commodity codes can override the density rule for certain items.
How to calculate your freight class (3 steps)
- Get cubic feet. Multiply length x width x height (in inches), then divide by 1,728. Example: a 48 x 40 x 48 in pallet = 92,160 / 1,728 = 53.33 cubic feet.
- Get density in PCF. Divide total weight (lbs) by cubic feet. Formula:
density (lb/ft3) = weight / (L x W x H / 1728) - Map density to class. Use the NMFTA density table below. A 500 lb pallet at 53.33 cubic feet = 9.4 PCF = Class 100. Verify the NMFC item number for your commodity before booking; commodity-specific overrides exist.
Common NMFC items mapped to freight class
Industry-standard freight class assignments for common LTL commodities. Use as a quick reference; verify the active NMFC tariff for the exact item number before quoting or booking.
NMFC item numbers shown are commodity-family approximations from the NMFTA classification. Sub-numbers differ by packaging, palletization, and condition. Cross-reference your active tariff before booking.
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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 do I calculate my freight class?
Three steps. (1) Cubic feet: multiply length x width x height (in inches), then divide by 1,728. (2) Density: divide total weight (lbs) by cubic feet. Formula: density (lb/ft3) = weight / (L x W x H / 1728). (3) Map density to class using the NMFTA table: 50+ PCF = Class 50, 35-50 = 55, 30-35 = 60, 22.5-30 = 65, 15-22.5 = 70, 13.5-15 = 77.5, 12-13.5 = 85, 10.5-12 = 92.5, 9-10.5 = 100, 8-9 = 110, 7-8 = 125, 6-7 = 150, 5-6 = 175, 4-5 = 200, 3-4 = 250, 2-3 = 300, 1-2 = 400, under 1 = 500. NMFC commodity codes can override density.
What freight class is auto parts?
Auto parts NOI typically classify as Class 70 (15-22.5 PCF). Specific items differ: brake rotors palletized = Class 55, brake pads boxed = Class 65, alternators = Class 70, bumpers (plastic or rubber) = Class 70, engines crated = Class 55. Always cross-reference the specific NMFC item number for the part type.
What freight class is electronics?
Consumer electronics packaged for shipping typically classify as Class 125 (7-8 PCF). Lighter items like air purifiers run Class 150 to 200. Heavier industrial electronics and capacitors often fall in the Class 77.5 to 100 range. Original boxed packaging with foam adds volume without weight, raising class. Condensing packaging can lower the class and the rate.
What freight class is wood furniture?
Wood furniture knocked down (KD) flat in boxes ships as Class 85. Wood furniture set up (assembled) is Class 100. Upholstered furniture ranges Class 125 to 250 depending on KD vs assembled. Bookcases knocked down are Class 110. Whether the piece ships flat or assembled is the single biggest driver of furniture freight class.
Why does freight class matter for LTL pricing?
Freight class is the primary input to LTL rate calculation. Carriers multiply weight by a per-hundredweight rate that varies by class. Class 50 freight pays the lowest per-pound rate; Class 500 pays the highest. A shipment misclassified one tier higher (for example Class 100 quoted as Class 70) can cost 15-35% more after the carrier reclassifies at the terminal. Reclassification charges are one of the most common LTL invoice disputes because they apply after delivery as back-bills that bypass the original quote.
What's the difference between NMFC and freight class?
NMFC (National Motor Freight Classification) is the commodity coding system; freight class is the pricing tier output. NMFC assigns each commodity a specific item number (for example NMFC 156600 for plastic parts NOI) plus rules covering density, stowability, handling, and liability. The freight class (50 to 500) is what the NMFC item number resolves to for billing. Most freight gets its class from density alone, but certain NMFC items have a fixed class regardless of density. The NMFTA publishes both: the NMFC item number is the lookup; the freight class is the price band.
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.
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.