0.0283168 — the number on every Bill of Lading
International freight is billed in CBM (cubic meters) almost everywhere, but US domestic moves and many legacy quotes still list cargo in CFT (cubic feet). The translation between them is one constant: 1 ft³ = 0.028316846592 m³. A Bill of Lading that reads 67.7 CBM for a 40-foot container is really stating 2,390 cubic feet in SI clothing. Miss the conversion and a consolidator either under-bills a full container or rejects a shipment that "doesn't fit" the booked volume.
Why cubing the foot makes a small number
The factor is not arbitrary. One foot is exactly 0.3048 meters, so one cubic foot is (0.3048 m)³ — and 0.3048 × 0.3048 × 0.3048 = 0.028316846592. Two consequences follow. First, the number is exact, not measured, so there is no uncertainty in the constant itself. Second, cubing amplifies any shortcut: truncating to 0.0283 instead of the full value ships a 0.06% error. That is nothing for a ventilation calculation but everything when natural gas is custody-transferred in the millions of cubic feet and the bill is computed from the converted volume.
The container that is 67.7 m³ (and 2,390 ft³)
The standard 40-foot dry container has an internal volume around 2,390 ft³. Run it through ×0.0283168 and you get ~67.7 m³ — the figure ocean carriers use for rate tiers and stowage plans. A 20-foot container is roughly half that, about 33.2 m³ (1,172 ft³). The same arithmetic sizes a room: 1,000 ft³ is 28.32 m³, the volume of a small storage unit; 100 ft³ is 2.83 m³, about the inside of a large refrigerator. The cubic meter is simply the cubic foot rescaled into the unit the world's ports agree on.
Dimensional weight: when air freight bills the bigger number
Air cargo turns this volume into money through dimensional (volumetric) weight. A box may weigh 10 kg but occupy a volume whose cubic-meter figure, multiplied by a carrier factor, "weighs" 18 kg — and the airline bills the larger of the two. So the cubic-feet-to-cubic-meters step is not just descriptive; it directly sets the price. Get it wrong by a decimal place and a lightweight shipment is quoted as heavy, or a dense shipment sneaks under the threshold and the carrier loses revenue. Either way, the 0.0283168 constant is doing real financial work.
Cubic-feet-to-cubic-meters reference values
| cu ft | cu m | What it represents |
|---|---|---|
| 1 cu ft | 0.0283 cu m | Definition — one cubic foot. |
| 100 cu ft | 2.832 cu m | A large refrigerator. |
| 1,000 cu ft | 28.32 cu m | A small storage room. |
| 1,172 cu ft | 33.2 cu m | A 20-foot container. |
| 2,390 cu ft | 67.7 cu m | A 40-foot container. |
Frequently asked questions
How do I convert cubic feet to cubic meters?
Multiply the number of cubic feet by 0.0283168. The exact factor is 0.028316846592, which is 0.3048 cubed — because one foot is exactly 0.3048 m, so one cubic foot is (0.3048 m)³. So cu m = cu ft × 0.028316846592.
Where is cubic-feet-to-cubic-meters used daily?
International shipping above all: freight is billed in CBM (cubic meters) worldwide but quoted in CFT (cubic feet) for US domestic moves. A 40-ft container is about 2,390 ft³ or 67.7 m³. HVAC airflow (CFM vs m³/s) and natural-gas metering use the same step.
How many cubic meters is 100 cubic feet?
100 cu ft × 0.0283168 = 2.83168 cu m. Air freight uses this volume for dimensional (volumetric) weight, billing the larger of the actual weight and the volume converted at a fixed factor — so the cubic-meter figure often decides the price.
Engineering context
Cubic feet to cubic meters (1 ft³ = 0.0283168466 m³) is derived by cubing the foot definition, (0.3048 m)³, so the constant itself is exact. The discipline is to carry the full value until the reported result, because cubing magnifies any truncation — negligible for room ventilation, significant for custody-transfer of natural gas where volumes reach millions of cubic feet. The same step appears in HVAC (CFM vs m³/s) and in container stowage, where the converted CBM drives rate tiers. Keep one canonical unit internally (cubic meters for any SI drawing or Bill of Lading) and convert only at the interface with a cubic-foot measurement. The deep walkthrough for this volume pair is at cubic meters to cubic feet; the adjacent liquid steps are gallons to liters, liters to gallons, and liters to ml, with the full topic in the Volume conversion guide.