CBM to kg: How Volume Becomes Chargeable Weight
There is no single figure for CBM to kg, because a cubic metre of feathers and a cubic metre of steel do not weigh the same. What carriers use is a conversion rule: in sea freight 1 CBM counts as 1,000 kg, in air freight as 166.67 kg, and with express couriers as 200 kg.
The rule depends on how the goods travel
| Mode | Volume to weight rule | What you are charged on |
|---|---|---|
| Sea freight, LCL (weight or measure) | 1 CBM = 1,000 kg (1 tonne) | The greater of the volume in CBM and the weight in tonnes |
| Air freight (divisor 6,000) | 1 CBM = 166.67 kg | The greater of the volumetric weight and the actual weight |
| Express couriers (divisor 5,000) | 1 CBM = 200 kg | The greater of the volumetric weight and the actual weight |
| Road freight in Europe (a common rule) | 1 CBM = 333 kg | Varies by carrier and country: check your carrier |
These are the rules most carriers publish. A carrier can set its own divisor, so confirm it on your quotation.
Sea freight: weight or measure (W/M)
Less than container load (LCL) sea freight is charged per revenue tonne: 1 CBM or 1,000 kg, whichever is greater. Compare the volume in CBM with the weight in tonnes and pay on the larger number.
Example. 8 CBM weighing 3,200 kg: 8 against 3.2, so 8 revenue tonnes (charged on volume). 2 CBM weighing 5,000 kg: 2 against 5, so 5 revenue tonnes (charged on weight).
Air freight: volumetric weight
Volumetric weight in kg = length × width × height in cm ÷ 6,000, which is the same as CBM × 166.67. The chargeable weight is the greater of that and the actual gross weight.
Example. 1.2 CBM weighing 150 kg: 1.2 × 166.67 = 200 kg volumetric, so 200 kg is charged. The same 1.2 CBM weighing 260 kg is charged at 260 kg.
Express couriers usually divide by 5,000 instead: 1.2 CBM × 200 = 240 kg.
CBM to metric tons
For sea freight, 1 CBM is treated as 1 metric ton (1,000 kg) when working out the charge. That is a pricing rule, not the weight of the cargo. The real weight still has to stay within the container payload and the road limits on the route.
The real weight: density
To know what a cubic metre of your own goods weighs, divide the gross weight by the volume: density in kg per CBM = total kg ÷ total CBM.
Example. 900 cartons, 9,200 kg, 51.75 CBM: 9,200 ÷ 51.75 = 178 kg per CBM. That is below 1,000, so by sea this shipment is charged on volume; it is above 166.67, so by air it would be charged on actual weight.
Common questions
How many kg is 1 CBM?
It depends on the goods. For charging, 1 CBM counts as 1,000 kg by sea, 166.67 kg by air and 200 kg with most express couriers.
How do I convert 3 CBM to kg?
By sea: 3 × 1,000 = 3,000 kg (3 revenue tonnes). By air: 3 × 166.67 = 500 kg volumetric. With a courier: 3 × 200 = 600 kg.
How do I convert kg to CBM?
You cannot from the weight alone: you need the size of the cartons. Measure them and use the calculator below.
Next step
Open the CBM Calculator Volumetric Weight Calculator
The CBM Calculator shows the sea W/M figure and the air and courier chargeable weight for your shipment. The Volumetric Weight Calculator covers single parcels and other divisors.