Freight class calculator guide
What does this calculator help you figure out?
Every LTL shipment in the United States and Canada is rated against a freight class between 50 and 500, and for most commodities that class follows density: heavy, compact freight gets a low class and a low rate, bulky, light freight gets a high class and a high rate. This calculator multiplies the length, width, and height of each handling unit in inches, converts to cubic feet, divides the total weight in pounds by that volume, and looks up the resulting pounds per cubic foot on the NMFC density scale. Shippers use it to fill in the class box on a bill of lading, to check a quote, and to see how much a taller pallet or a heavier load moves the class. It gives the density-based class only. Items that the NMFC assigns a fixed class regardless of density, and freight rated up for fragility, hazard, liability, or stowability, are for your carrier to confirm.
How is the result calculated?
Total volume (ft³) = length (in) × width (in) × height (in) ÷ 1,728 × units. Total weight (lb) = weight per unit × units. Density (lb/ft³) = total weight ÷ total volume. Class = NMFC density band containing that density (≥ 50 lb/ft³ → 50; 9–10.5 → 100; < 1 → 500).
Worked example
Worked example: one pallet of boxed goods measures 48 in × 40 in × 48 in including the pallet and weighs 500 lb. Volume is 48 × 40 × 48 = 92,160 cubic inches, which is 92,160 ÷ 1,728 = 53.33 ft³. Density is 500 ÷ 53.33 = 9.38 lb/ft³. On the NMFC density scale 9 to 10.5 lb/ft³ is class 100. Had the same goods weighed 600 lb the density would be 11.25 lb/ft³ and the class 92.5; had they been stacked to 60 in tall at 500 lb the density would fall to 7.5 lb/ft³ and the class rise to 125. The calculator displays Class 100 at a density of 9.38 lb/ft³.
Units and conversion notes
Dimensions are in inches and weight in pounds per handling unit, the way US carriers measure and the way the NMFC scale is written. Measure the loaded pallet at its tallest and widest points, including the 5 to 6 inches of pallet height and any overhang, and use the gross weight with packaging. For centimetres divide by 2.54 and for kilograms multiply by 2.2046 before entering. Units is the number of identical pallets or crates; the calculator totals volume and weight before dividing.
What does the result mean?
Carriers bill on whichever is greater, actual weight or volumetric weight, so treat this result as the number to compare against your carrier's own quote. Divisors, rounding rules, and surcharges differ between carriers and between domestic and international services, and they change with contract terms. Confirm the current rules for your account before you price a shipment. On this page the figure rests entirely on length, width, height, weight per unit, units, market / jurisdiction, effective date, data source, update owner and review date, so start there if the freight class calculator returns something you did not expect.
Common mistakes to avoid
Good to know: the pallet is part of the shipment, so leaving out its height or weight moves the density. A 48 × 40 × 48 in unit at 500 lb is class 100, but the same goods measured without the pallet at 42 in tall would compute to 10.71 lb/ft³ and class 92.5, and the carrier would re-weigh and re-measure it back to 100 and bill the difference. Do not average pallets of different sizes by hand; enter them as separate shipments. A density class is also not the end of the story for freight the NMFC lists under a commodity item with its own class.
Shipping results depend on carrier, service, route, divisor, rounding, surcharges, and contract terms. Confirm the current carrier rule before buying a label or quoting a customer.
Common questions
Frequently asked questions
What is the NMFC density scale for freight class?
The scale runs: 50 lb/ft³ and above class 50; 35–50 class 55; 30–35 class 60; 22.5–30 class 65; 15–22.5 class 70; 13.5–15 class 77.5; 12–13.5 class 85; 10.5–12 class 92.5; 9–10.5 class 100; 8–9 class 110; 7–8 class 125; 6–7 class 150; 5–6 class 175; 4–5 class 200; 3–4 class 250; 2–3 class 300; 1–2 class 400; under 1 class 500.
Why does freight class matter for LTL shipping rates?
LTL carriers price per hundredweight against a class-based tariff, so the class is a multiplier on the whole freight bill. Moving one class band, from 100 to 110 or 125, commonly adds 10 to 25 per cent to the linehaul charge for the same weight and lane, and the gap widens sharply above class 150 where the space a shipment takes becomes the real cost.
What is the difference between density-based and commodity-based class?
Many NMFC items say “class based on density” and use the scale above. Others assign a single class to a commodity no matter how it is packed, because of value, fragility, or liability: for example most new furniture, engines, or hazardous chemicals have listed classes. Look the commodity up in the NMFC first; use density only where the item calls for it.
What happens if I put the wrong freight class on the bill of lading?
Carriers weigh and measure freight on the dock and issue a reclassification if the density does not support the class. You pay the rate at the corrected class plus a reweigh or inspection fee, commonly 20 to 50 dollars per shipment, and repeated corrections can void a negotiated discount. Underclassing to save money almost always costs more than declaring accurately.
What freight class is a standard pallet weighing 500 pounds?
It depends on height. A 48 × 40 in pallet loaded to 48 in tall at 500 lb has a density of 9.38 lb/ft³ and is class 100. Loaded to 36 in it is 12.5 lb/ft³ and class 85; loaded to 60 in it is 7.5 lb/ft³ and class 125. Keeping the stack low and the load heavy is the cheapest way to move density.
