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CBM Calculator
CBM is cargo volume in cubic meters, and this CBM calculator totals it for any mix of cartons, crates or pallets measured in centimeters, millimeters, meters, inches or feet. With weights added, it shows what the shipment bills as: revenue tons for sea LCL, and chargeable weight for air (cm³ ÷ 6,000) and express (cm³ ÷ 5,000). One cubic meter is 35.31467 cubic feet.
- Multiple carton sizes
- Sea W/M, air and express chargeable weight
- 20 ft, 40 ft and high cube fill
CBM calculator
Cartons, crates or pallets in; cubic meters, cubic feet and chargeable weight out. Updates as you type.
CBM rarely decides the bill on its own
A cubic meter figure is where a freight quote starts, not always where it ends. Sea freight rated weight or measure charges on the larger of the cubic meters and the metric tonnes. Air and express carriers turn volume into a weight and charge the heavier of that and the scale weight. Three rules, and the CBM wins only some of the time.
Press Try an example under the calculator to see the split: 40 cartons of 60 × 40 × 40 cm at 18 kg each and 12 crates of 120 × 80 × 100 cm at 210 kg each. That is 52 pieces, 15.36 m³ and 3,240 kg.
| Mode | Volume counts as | Volume side | Weight side | Bills on |
|---|---|---|---|---|
| Sea LCL (W/M) | 1 m³ against 1,000 kg | 15.36 RT | 3.24 RT | Volume: 15.36 RT |
| Air | cm³ ÷ 6,000 = kg | 2,560 kg | 3,240 kg | Weight: 3,240 kg |
| Express | cm³ ÷ 5,000 = kg | 3,072 kg | 3,240 kg | Weight: 3,240 kg |
By sea, the CBM is the bill: 15.36 beats 3.24, so the shipment pays for 15.36 revenue tons. By air the volume drops out. At the air divisor 15.36 m³ is worth 2,560 kg, less than the cargo weighs, so the carrier charges 3,240 kg. Express gets closer at 3,072 kg and still loses.
Check the density and you know the answer
Divide weight by volume before anyone quotes. The example is 3,240 ÷ 15.36, about 211 kg per cubic meter. Sea W/M switches from volume to weight at 1,000 kg per m³, because each cubic meter is set against a tonne. Express at ÷ 5,000 switches at 200, and air at ÷ 6,000 at about 166.67.
Freight lighter than 166.67 kg per m³ bills on volume by all three; freight heavier than 1,000 bills on weight by all three. In between, the CBM sets the price on one mode and not on another, which is why a CBM calculator for shipping has to go past the volume. The line under the result tiles names the basis each mode is billing on: sea, air and express.
How to calculate CBM in any unit
The CBM formula is length × width × height in meters, times the number of identical pieces. Any other unit is the same multiplication plus one division.
| Measured in | L × W × H gives | Divide by | Example | CBM |
|---|---|---|---|---|
| Meters | m³ | Nothing | 0.6 × 0.4 × 0.4 m | 0.096 |
| Centimeters | cm³ | 1,000,000 | 60 × 40 × 40 cm = 96,000 cm³ | 0.096 |
| Millimeters | mm³ | 1,000,000,000 | 600 × 400 × 400 mm = 96,000,000 mm³ | 0.096 |
| Inches | in³ | 61,023.74 | 48 × 40 × 48 in = 92,160 in³ | 1.5102 |
| Feet | ft³ | 35.31467 | 4 × 3.333 × 4 ft = 53.333 ft³ | 1.5102 |
Going from cm to CBM, the carton above is 0.096 m³ and 40 of them make 3.84. Keep the decimals until the total. Round each carton up to 0.1 m³ first and those 40 become 4.0 m³, about 4% more space than you are shipping.
Inches to CBM: don't divide by 1,728
1,728 is the number of cubic inches in a cubic foot, so dividing by it gives cubic feet. The 48 × 40 × 48 inch pallet in the table is 92,160 in³. Over 1,728 that is 53.333 ft³; over 61,023.74 it is 1.5102 m³. Book 53.333 as CBM and you have claimed about 35 times the space.
NIST Handbook 44 puts a cubic meter at 61,023.74 cubic inches, and any CBM calculator working in inches should divide by that. Choose Inches under Dimensions in and this one does.
CBM to CFT: cubic meters to cubic feet and back
Multiply cubic meters by 35.31467 to get cubic feet. To convert cubic feet to cubic meters, multiply by 0.02831685. Both factors are NIST's, and CFT, cu ft and CBF all name the same cubic foot on forwarders' paperwork. So 10 m³ is 353.15 ft³, the example's 15.36 m³ is 542.43 ft³, and 1,000 ft³ is 28.317 m³.
The Cubic feet tile converts the whole shipment. For a single figure off a packing list, use the CBM ⇄ cubic feet box under the result; it ignores the lines above, so your shipment stays as it was.
Inside the US, CBM stops mattering once freight moves by LTL truck. LTL carriers price on NMFC freight class, which for density-rated freight comes from pounds per cubic foot. If the cartons go on by LTL after they land, put the same measurements through the freight class calculator.
CBM meaning in shipping: W/M and the revenue ton
On the ocean a cubic meter is a billing unit as much as a measurement. The Port of Los Angeles puts it plainly: "1 Revenue Ton (RT) can equal 1 metric ton OR 1 cubic meter." Cargo rated weight or measure, written W/M, pays on whichever gives the higher revenue.
LCL, less-than-container-load freight sharing a box with other shippers' cargo, is where that rule does its work. Shapiro, a US customs broker, says most LCL is priced on the higher of 1,000 kg or 1 m³, and that some trades use other bases, such as 100 lb or 1 cubic foot for Hawaii, Alaska and Puerto Rico. On those lanes the Sea LCL (revenue tons) tile is not your basis.
A 100 × 50 × 40 cm box of 20 kg is 0.2 m³ against 0.02 tonnes, so it bills 0.2 revenue tons on volume. A 100 × 100 × 50 cm crate at 900 kg is half a cubic meter but bills 0.9 RT on weight. If a forwarder consolidates your cartons under its own house bill of lading, the cubic meters and the gross kilograms both go on it.
CBM to kg: volumetric weight and chargeable weight
There is no CBM to kg conversion. One is space and the other is mass; a cubic meter of pillows and a cubic meter of bolts share only the first number. Air and express carriers bridge the gap with a divisor that turns volume into volumetric weight, then bill the chargeable weight, the larger of that and the scale weight.
- Air cargo, ÷ 6,000. IATA's rule divides cubic centimeters by 6,000, so 1 m³ counts as about 166.67 kg. The Air chargeable weight tile uses it.
- DHL Express, ÷ 5,000. In DHL's words, 1 m³ = 200 kg. The Express chargeable weight tile uses it.
- FedEx in the US, ÷ 139. Cubic inches to pounds; a cubic meter comes to about 439 lb that way, or 199 kg.
- Another metric divisor. Multiply the total CBM by 1,000,000 for cubic centimeters and divide by it.
5,000 against 6,000 on the same cartons
A smaller divisor makes a bigger weight: 5,000 gives 20% more than 6,000. The example's 40 cartons, 3.84 m³ at 720 kg, are worth 640 kg by air, so they bill 720 kg on weight. By express they are worth 768 kg and bill on volume. Same cartons, different basis.
20 ft and 40 ft container CBM, and the space you can fill
The fill bars under the result measure the shipment against Hapag-Lloyd's published figures.
| Container | Volume (Hapag-Lloyd) | Volume (Maersk) | Max payload (Hapag-Lloyd) | 15.36 m³ fills |
|---|---|---|---|---|
| 20 ft standard | 33.2 m³ | 33.2 m³ | 28,130 kg | 46.3% |
| 40 ft standard | 67.7 m³ | 67.7 m³ | 28,750 kg | 22.7% |
| 40 ft high cube | 76.3 m³ | 76.4 m³ | 28,600 kg | 20.1% |
Hapag-Lloyd calls these examples from its own fleet, and Maersk's high cube is 0.1 m³ bigger. No carrier publishes a usable volume. Freightos, a freight booking platform, calls "a little over 80%" of the maximum a rule of thumb: on that rule, a little over 26.6 m³ in a 20 ft and 54.2 m³ in a 40 ft.
Weight can run out first. A 40 ft holds about twice a 20 ft's volume but only 620 kg more payload. Load one with cargo denser than about 425 kg per m³ (28,750 ÷ 67.7) and the payload runs out before the space does. A bar reads over payload when your total passes a container's published payload, and needs 2 when the volume takes two boxes.
Palletized cargo can run out of floor instead. At Hapag-Lloyd's published inside dimensions a 20 ft takes 9 standard 48 × 40 pallets and a 40 ft takes 20; the page on how many pallets fit in trailers and containers shows the layouts.
Mixed carton sizes, missing weights and saving the result
Give each carton or pallet size its own line, with its Quantity, dimensions and Weight each, and press + Add line for the next; up to 50 lines fit. For pallets, build them in the pallet calculator first and enter each finished pallet size here.
Weights are optional, but the calculator is strict about them. Leave one line without a weight and Gross weight, the sea figure and both chargeable weights show a dash, because a total from some of the weights would understate every charge. Volume, cubic feet and container fill still work, so it doubles as a plain cubic meter calculator.
Copy results gives you every figure and its billing basis as text for a booking email. Share link reopens the same lines, which travel after the # in the link. Save in this browser keeps it on this device; Download CSV opens in Excel.
What these figures leave out
The calculator measures and compares; it doesn't price. It holds no rates or forwarder's charges, its fill bars use full internal volume, and its sea figure assumes the cubic meter against tonne rule. When a quote disagrees, ask which divisor and basis it used.
Questions about CBM and chargeable weight
How do I calculate CBM?
Multiply length × width × height in meters, then multiply by the number of identical pieces. From centimeters, divide the cubic centimeters by 1,000,000; from inches, divide the cubic inches by 61,023.74. A 60 × 40 × 40 cm carton is 96,000 cm³, or 0.096 m³, so 40 of them are 3.84 CBM. For several sizes, work out each one the same way and add them together.
How many CBM is 1 kg?
None. CBM measures space and kilograms measure mass, so there is no conversion, only billing equivalents. Sea freight rated weight or measure sets 1 m³ against 1,000 kg, so 1 kg stands in for 0.001 m³. Air cargo divides cubic centimeters by 6,000, making 1 chargeable kilogram worth 0.006 m³. DHL Express divides by 5,000: 1 kg equals 0.005 m³.
How to calculate CBM of a 40 feet container?
Multiply its inside length, width and height in meters. Hapag-Lloyd publishes a 40 ft standard at 12,032 × 2,352 × 2,395 mm inside, which multiplies out to about 67.78 m³; the line lists 67.7 m³, and so does Maersk. A 40 ft high cube is listed at 76.3 m³ by Hapag-Lloyd and 76.4 m³ by Maersk. Real cargo fills less than either.
Is CBM equal to m³?
Yes. CBM is short for cubic meter, so 1 CBM and 1 m³ are the same volume, and a quote for 15.36 CBM means 15.36 m³. NIST's conversion tables put one cubic meter at 35.31467 cubic feet, 61,023.74 cubic inches and 1.307951 cubic yards. The calculator's headline tile, Total CBM (m³), carries both names for that reason.
How do you calculate CBM with inches?
Multiply length × width × height in inches and divide the cubic inches by 61,023.74. A 48 × 40 × 48 inch pallet is 92,160 cubic inches, or 1.5102 m³. Don't divide by 1,728: that gives cubic feet, and the same pallet comes out at 53.333, about 35 times its real CBM. In the calculator, choose Inches under Dimensions in.
How do I calculate CBM for multiple boxes?
Work out one box of each size, multiply it by how many of that size there are, and add the sizes together. The calculator takes one line per size with a quantity on each. Its built-in example has 40 cartons of 60 × 40 × 40 cm (3.84 m³) and 12 crates of 120 × 80 × 100 cm (11.52 m³), 15.36 m³ in total.
What is volumetric weight and why does it matter?
Volumetric weight is volume turned into kilograms with a divisor, so light, bulky cargo pays for the space it takes. Air and express carriers bill the larger of volumetric and actual weight, called the chargeable weight. At IATA's divisor of 6,000, a 100 × 50 × 40 cm box of 20 kg bills as 33.33 kg by air. At DHL Express's 5,000 it bills as 40 kg.
What is the difference between DIM factor 5000 and 6000?
Dividing by 5,000 gives a chargeable weight 20% higher than dividing the same volume by 6,000: 1 m³ counts as 200 kg rather than about 166.67 kg. IATA's air cargo rule uses 6,000; DHL Express uses 5,000. Forty cartons of 3.84 m³ and 720 kg bill on their 720 kg weight at 6,000, but on 768 kg of volume at 5,000.
What is the usable capacity of a shipping container?
No carrier publishes one. The published figures are internal volumes: Hapag-Lloyd lists 33.2 m³ for a 20 ft, 67.7 m³ for a 40 ft and 76.3 m³ for a 40 ft high cube. Freightos, a freight booking platform, gives a rule of thumb of a little over 80% of the maximum: a little over 26.6 m³ in a 20 ft.
What is CBM in shipping?
CBM is the cubic meter, the unit international shipping uses for cargo volume. In sea LCL it is half the billing rule: the Port of Los Angeles defines a revenue ton as 1 metric ton or 1 cubic meter, and cargo rated weight or measure (W/M) pays on whichever gives more. The same figure shows how much of a container a shipment takes.