How to Calculate Freight Density for LTL Shipping
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The freight density formula
Freight density is simply weight divided by volume, expressed in pounds per cubic foot (PCF):
Density (PCF) = Total weight (lbs) ÷ Total volume (cubic feet)
To get volume in cubic feet from inches, multiply length × width × height (all in inches) and divide by 1,728 (the number of cubic inches in a cubic foot):
Volume (cu ft) = (L × W × H in inches) ÷ 1,728
Put together: weigh the fully packaged unit, measure its three dimensions at the widest points, compute volume, then divide weight by volume. That single PCF figure is what carriers use to land most commodities in their class band.
How to measure a pallet correctly
The most common density mistakes are measurement mistakes. A few rules keep you out of a reclassification fee:
- Measure the packaged unit, not the product. Include the pallet, the box, shrink wrap, and any overhang.
- Measure to the extremes. If anything bulges past the pallet footprint, measure to the furthest point — carriers rate the space the freight actually occupies.
- Round height up to the highest point, including a domed top or protruding hardware.
- Weigh the whole thing, pallet included, on a certified scale. Estimated weights are a frequent rebill cause.
- Multiple pieces: sum the weight of all pieces and sum the volume of all pieces, then divide once for the shipment's overall density.
Density-to-freight-class table
Once you have PCF, this table gives the standard density-based class. It is the starting point — the binding answer is always the commodity's actual NMFC provision, which can fix or scale the class regardless of density (see How to Determine Freight Class).
| Density (PCF) | Freight class |
|---|---|
| 50+ PCF | 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 |
Worked examples
Example 1 — a dense pallet of parts. A pallet measures 48 × 40 × 48 inches and weighs 900 lbs. Volume = (48 × 40 × 48) ÷ 1,728 = 53.3 cu ft. Density = 900 ÷ 53.3 = 16.9 PCF → class 70.
Example 2 — a light, bulky pallet. Same 48 × 40 × 48 footprint but only 120 lbs. Volume = 53.3 cu ft. Density = 120 ÷ 53.3 = 2.25 PCF → class 300. Same box size, very different class — this is why bulky-but-light freight is expensive.
Example 3 — the boundary case. A pallet at 14 PCF is class 77.5; add an inch of height that drops it to 13.4 PCF and it becomes class 85. Near a band edge, careful measurement (or tighter packaging) directly changes your rate. See Freight Class 77.5 for that band specifically.
Skip the arithmetic with the free Freight Class Calculator — enter dimensions and weight and it returns density and the standard class instantly. To rate at scale inside a TMS, the NMFC API returns class and density programmatically.
Frequently asked questions
What is the freight density formula?
Density (pounds per cubic foot) = total weight in pounds divided by total volume in cubic feet. Get cubic feet by multiplying length x width x height in inches and dividing by 1,728.
How do I calculate the cubic feet of a pallet?
Multiply length x width x height (all in inches) and divide by 1,728. For example, a 48 x 40 x 48 inch pallet is (48 x 40 x 48) / 1,728 = 53.3 cubic feet.
Does higher density mean a lower freight class?
Yes. Denser freight (more pounds per cubic foot) gets a lower class number and a cheaper rate per pound. Light, bulky freight gets a higher class.
Is density the only thing that sets freight class?
For most commodities density drives the class, but the commodity\u2019s actual NMFC provision can fix or scale the class for stowability, handling, or liability regardless of density.
Related guides
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