How do I calculate freight class?

Measure the shipment in inches including any overhang, multiply length × width × height and divide by 1,728 for cubic feet, divide the weight in pounds by that for lb/ft³, and read the class off the NMFC density scale. Then check the NMFC item, which decides.

Is the calculator's class the final class?

Only if your commodity is classed by density. Many NMFC items carry a fixed class, so treat the result as an estimate and confirm it against the item before shipping.

What changed in the NMFC density scale in 2025?

Docket 2025-1, effective 19 July 2025, replaced the 11-step density scale with a 13-step one and moved more than 2,000 items to density-based classification.

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Freight Class Calculator

Enter a shipment's size and weight to get its density in lb/ft³ and an estimated freight class on the NMFC's 2025 density scale — then confirm the class against the NMFC item.

Your shipment

Length, including overhang

Width, including overhang

Height

Number of pieces

Total weight

Estimated freight class

Class 100

Density: 9lb/ft³
Density band: 8 to under 10 lb/ft³
Total volume: 50ft³

An estimate from density alone. The NMFC item for the commodity decides the class — many items have a fixed class.

How the class is estimated

Density (lb/ft³) = weight (lb) ÷ (length × width × height in inches ÷ 1,728)

Measure the full shipment, including every overhang and projection, as NMFTA's method says. Then read the class off the NMFC's 13-step density scale, in force since 19 July 2025.

Worked example

NMFTA's own example, and the calculator's opening values: a 48 × 40 × 45 in pallet weighing 450 lb is 86,400 in³ ÷ 1,728 = 50 ft³, so its density is 450 ÷ 50 = 9 lb/ft³. On the 2025 scale, 8 to under 10 lb/ft³ is class 100.

When the answer misleads

Whenever the commodity is not classed by density. The NMFC lists each commodity as an item, and many items carry a fixed class set by handling, stowability and liability as well as density — this calculator cannot know which item your freight falls under. Use it to estimate and to check a quote, then confirm the class against the NMFC item before it goes on the bill of lading.

FAQ

Freight Class Calculator: common questions

How do I calculate freight class?: Measure the shipment in inches including any overhang, multiply length × width × height and divide by 1,728 for cubic feet, divide the weight in pounds by that for lb/ft³, and read the class off the NMFC density scale. Then check the NMFC item, which decides.
Is the calculator's class the final class?: Only if your commodity is classed by density. Many NMFC items carry a fixed class, so treat the result as an estimate and confirm it against the item before shipping.
What changed in the NMFC density scale in 2025?: Docket 2025-1, effective 19 July 2025, replaced the 11-step density scale with a 13-step one and moved more than 2,000 items to density-based classification.