Freight Density Calculator — kg/CBM, lb/ft3, Freight Class, Dim Weight
Answer: A freight density calculator divides gross weight by packed volume to show kg/CBM and lb/ft3, which helps estimate LTL freight class, air dimensional-weight risk, and ocean LCL W/M billing.
9 to <10.5 lb/ft³; density class only, official NMFC class can differ.
Break-even density is 166.7 kg/CBM with divisor 6000.
Ocean LCL commonly compares metric tons with CBM under the W/M revenue-ton rule.
A freight density calculator divides gross weight by packed volume to show kg/CBM and lb/ft3, which helps estimate LTL freight class, air dimensional-weight risk, and ocean LCL W/M billing.
How the calculation works
Freight density starts with the outer packed dimensions, not bare product size:
CBM = length x width x height x quantity, converted to cubic meters.
Density in kg/CBM = total gross weight in kg / total CBM.
Density in lb/ft3 = total gross weight in pounds / total cubic feet.
The calculator then uses the density in three practical ways. For US LTL, lb/ft3 maps to an estimated density freight class. For air freight, kg/CBM is compared with the dimensional-weight threshold: about 166.7 kg/CBM for a 6000 divisor and 200 kg/CBM for a 5000 divisor. For ocean LCL, density is compared with the W/M rule where 1 CBM is commonly treated as 1 revenue ton, equal to 1000 kg.
FAQ
How do I calculate freight density?
Measure the packed carton, pallet, or crate, calculate total volume, then divide gross weight by volume. Use kg/CBM for international freight planning and lb/ft3 for US LTL density-class planning.
What is kg per CBM?
Kg per CBM means kilograms of gross weight per cubic meter of packed cargo. A 500 kg shipment occupying 2 CBM has a density of 250 kg/CBM.
Why does freight density matter?
Density tells you whether cargo is light and bulky or dense and heavy. That affects aircraft space, LTL freight class, ocean LCL W/M billing, quote minimums, and the chance that a carrier bills by volume instead of actual weight.
How does density affect freight class?
US LTL density class commonly uses pounds per cubic foot. Lower density usually means a higher freight class and higher LTL cost, but official NMFC class can still depend on commodity, stowability, handling, liability, and carrier tariff rules.
What density makes air freight dimensional?
With the common 6000 cm3/kg air divisor, cargo below about 166.7 kg/CBM is usually volume-sensitive. With a 5000 divisor, the break-even density is 200 kg/CBM.
What density makes ocean LCL bill by weight?
Ocean LCL under W/M usually bills by weight only when cargo is above 1000 kg/CBM. Most ecommerce cartons are below that threshold and bill by measure, meaning CBM.
Should I use pallet dimensions?
Yes, if the freight moves on pallets. Density should use the outer packed space that the carrier actually handles, including pallet height, overhang, crates, and protective packaging.
Is freight density the same as chargeable weight?
No. Density is the ratio of weight to volume. Chargeable weight is the billable result after the carrier compares actual weight with volumetric weight or revenue tons.
Comparison table
| Metric | Formula | Best for | Related tool |
|---|---|---|---|
| Freight density | gross kg / CBM | Understanding cargo compactness | This calculator |
| LTL density class | lb / ft3 mapped to class table | US warehouse, 3PL, FBA prep, or final-mile LTL | Freight Class Calculator |
| Air dimensional weight | L x W x H cm / divisor | Air and courier billable-weight checks | Air Freight Dim Weight Calculator |
| Ocean LCL W/M | max(CBM, metric tons) | LCL ocean revenue-ton billing | Sea Freight Chargeable Weight Calculator |
| CBM | packed cubic meters | Container, LCL, and quote planning | CBM Calculator |
Dated facts
As of May 13, 2026, standard air cargo planning still commonly uses the 6000 cm3/kg divisor, which equals a density threshold of about 166.7 kg/CBM. Express courier planning often uses a 5000 divisor, equal to 200 kg/CBM. Ocean LCL planning commonly uses the W/M revenue-ton rule where 1 CBM is compared with 1 metric ton, and US LTL planning still uses density as a major input while allowing NMFC commodity rules, handling, stowability, liability, and carrier tariffs to override a density-only class.
Frequently asked questions
- How do you calculate freight density?
- Calculate packed volume, convert it to CBM or cubic feet, then divide gross weight by that volume. Freight density is kg/CBM for international planning and lb/ft3 for US LTL density class planning.
- Why does kg per CBM matter?
- Kg per CBM shows whether cargo is light and bulky or dense and heavy. It helps predict air dimensional weight, ocean LCL W/M billing, and how efficiently cargo uses container or aircraft space.
- How does density affect freight class?
- US LTL carriers often use pounds per cubic foot as one input to estimate density class. Official NMFC class can still change because commodity, stowability, handling, liability, and tariff rules also matter.
- What density makes air freight bill by dimensional weight?
- With a 6000 cm3/kg divisor, cargo below about 166.7 kg/CBM is usually volume-sensitive. With a 5000 divisor, the threshold is 200 kg/CBM.
- What density makes ocean LCL bill by weight?
- Ocean LCL commonly uses 1 CBM = 1 revenue ton. Actual weight usually beats measure only when cargo density is above 1000 kg/CBM.
- Should I use carton dimensions or product dimensions?
- Use outer packed carton, pallet, or crate dimensions because freight density is based on the space the shipment occupies after packaging.
- Is this the same as a chargeable weight calculator?
- No. This calculator explains density first and then shows billing implications. Use a chargeable-weight calculator when you only need the final billable weight.