How to calculate transport CBM?

Multiply length, width and height all in meters then multiply by the number of pieces. A box with dimensions 50cm x 80cm x 60cm has a volume of 0.5 x 0.8 x 0.6 = 0.24 cubic metres, and twenty boxes would be 4.8 CBM. If you are using centimetres multiply the three values then divide by 1,000,000. For inches divide by 61,024 and for feet divide by 35.3147. Measure the outside dimensions of your shipment including pallets and overhangs as this is what the freight forwarder will be selling space for.

How many cubic meters can be loaded into a single 20ft or 40ft container?

Geometrically speaking there are standard containers with a volume of about 33 cubic meters for the 20-footers and about 67 cubic meters for the 40-footers. The actual load capacity however is between about 25 and 28 as well as between 54 and 58. This is because cartons cannot be stacked perfectly and working space is needed. The discrepancies in published values are due to these empty spaces. An identical 20-footer can be stated at one location with 33 CBM and another with 26 to 28, both of which could be correct. This calculator treats the two cases separately. First it calculates the nominal volume from the internal dimensions, then a user-defined loading efficiency factor is applied. For mixed loads of cartons a value of 85% can be used as a reasonable starting point. With regular palletized loads up to 90% can be reached while with irregularly shaped goods the figure can drop down to 70%.

What is volumetric weight and what conversion factor should I use?

The volumetric weight converts the volume occupied by a shipment into a weight for which the freight forwarder charges. It is calculated by multiplying the three dimensions in centimeters and dividing it by the conversion factor used by the freight forwarder. For general air cargo shipments according to IATA, 6,000 is used, which equates approximately 167 kg per cubic meter. Most courier services (including DHL) use 5,000, resulting in 200 kg per cubic meter. Sea freight charges either 1 cubic meter or 1,000 kg, whichever is higher. This corresponds to a conversion factor of 1,000. Check the numbers given on the quote before relying on any particular value as they are negotiable and may vary by route.

Do I pay for actual weight or volume?

You pay for the higher of both. The freight forwarder calls this "chargeable weight", while ocean shippers talk about whether the charge is based on weight or volume. To make it simple: think of it as density. Calculate the kilograms per cubic meter for your shipment and compare that to the break-even point for each mode of transport. If the density exceeds 167 kg per cubic meter, then air freight charges are calculated on a weight basis. If it is below that, then they charge based on volume. For ocean shipping, the break-even point is at 1,000 kg per cubic meter, so most shipments (except metals and liquids) will be charged by volume. This simple comparison determines whether or not re-packaging makes sense in terms of cost-effectiveness.

Are CBM and volume the same thing?

Yes. CBM is just a shipping abbreviation for cubic meter volume. One CBM equals one cubic meter, which is approximately 35.3147 cubic feet or 1,000 liters. The only difference between CBM in shipping and the term "volume" in math class is that CBM always refers to the minimum volume of a box that can contain the cargo, not necessarily the volume of the cargo itself. If you pack a bike into a wooden crate, it will be billed by the volume of the wooden crate.

How many kilograms are in one cubic meter?

This depends entirely on the mode of transport. This is an important point. In shipping industry 1 CBM equals to a weight of 1,000 kg. According to IATA rules 1:6000 the weight for air freight is about 167kg. With shippers like 1:5000 it's 200kg. These are not measurements of the cargo but pricing guidelines. So the same pallet can be charged by an airline with 400 kg while a shipping company might charge per loaded tonne at 2.4.

When should you switch from a collective load to your own container?

A general rule of thumb across the industry is about 15 cubic meters. If below that volume a LCL is usually cheaper. Above that, the sum of the cubic price for an LCL plus the handling and terminal charges often exceeds the flat rate for a 20ft container. You also get faster processing and avoid the risk of having to share a container with others. Use the table below to do your own calculations. Enter in the cost of an LCL, read off the calculated volume and compare it against a flat rate offer from other companies for a dedicated container.

How do I calculate the volume (cbm) of cylindrical or irregularly shaped packages?

You use the smallest possible rectangular shape that will fit around your item. For cylindrical objects carried upright, most shippers count the circle as a square and treat the diameter as both width and height. So a cylindrical barrel with a 60 cm diameter and a 90 cm height would be calculated at 0.6 x 0.6 x 0.9 = 0.324 CBM. However, some shippers will accept the actual volume of the cylinder, which is pi x radius x radius x length. The volume for that same barrel would be 0.254 CBM, so it's worth asking. For really irregularly shaped items you should measure the maximum length, width and height including any protruding parts.

CBM Shipping Calculator

Your shipment

How is it moving?

Ocean LCL - billed per cubic metre or tonne, whichever is greater

Air freight - IATA general cargo, 1:6000

Courier or express - 1:5000

My carrier uses a different divisor

Package length

Package width

Package height

Number of packages

Gross weight per package

Total volume (CBM)

Chargeable weight

Container fit

A container has two limits, not one: the space and the payload. This section checks both.

Check how it fits in a container

Compares your cargo against the container's space AND its payload limit.

Container

Stowage efficiency

Freight cost estimate

Please input values into the fields

Break-even density for this mode: kg/m³

Usable capacity per container: m³

CBM stands for cubic meters, and the CBM shipping calculator tool converts the three dimensions of a carton into figures that serve as basis for an actual freight rate calculation. It is calculated by length x width x height x quantity. This computation can be done in just ten seconds.

The real unnecessary expenses come after that. Shippers do not charge based on volume only. Instead, the weight and volume are converted to each other with a certain conversion factor, and the higher of both is charged. This factor varies depending on the type of transport and the shipper. Therefore this tool calculates not just cubic meters but also volumetric weight, chargeable weight, density which determines which value takes precedence, the fill rate in relation to the maximum volume and weight load of a container, as well as total costs based on the given freight price.

The formula for calculating CBM is as follows:

If each dimension is given in meters, then the volume of a single package can be easily calculated.

\text{CBM} = L \times W \times H

The total volume of the cargo is this value multiplied by the number of packages.

\text{Total CBM} = L \times W \times H \times Q

Since dimensions are almost never given in meters, it is usually represented in the same formula with a conversion factor. The following four representations will give the same calculated result.

You measured in	Formula	Why that number
Metres	L x W x H	Already cubic metres
Centimetres	L x W x H / 1,000,000	100 x 100 x 100 cm in a cubic metre
Millimetres	L x W x H / 1,000,000,000	1,000 x 1,000 x 1,000 mm in one
Inches	L x W x H / 61,023.7	1 m3 = 61,023.74 cubic inches
Feet	L x W x H / 35.3147	1 m3 = 35.3147 cubic feet

Measure the outside dimensions of your package. Do not use the dimensions of the product itself or standard carton sizes listed in technical data sheets. Measure the actual outside dimensions including pallets, shrink wrap and other protruding parts. Freight companies sell space on ships or planes and that space must be enough to accommodate even the most sticking out parts.

Example calculation:

Suppose there are twenty identical cartons with the dimensions of length 50 cm, width 80 cm, height 60 cm and a weight of 35 kg each.

The volume of a single carton is 0.5 x 0.8 x 0.6 = 0.24 cubic meters. The total volume for the twenty cartons is 4.8 CBM, which equates to 169.51 cubic feet. The total weight is 35 x 20 = 700 kg.

Next we calculate the price. For shipping services that use a conversion factor of 1:5000, the volumetric weight is 4.8 x 200 = 960kg. As this exceeds the actual weight of 700kg, a chargeable weight of 960kg will be calculated so you pay for 260kg of air.

If the same pallet shipment is converted to ocean freight, it will be calculated in different units. Ocean freight charges are charged per "chargeable ton", which is defined as the larger of either volume (cubic meters) or weight (tons). When comparing 4.8 CBM and 0.7 tons, the chargeable volume would be 4.8 "chargeable tons".

Volume weight and conversion factors

The volume weight, also called dimensional weight, exists because a pallet full of cushions and a pallet full of ball bearings take up the same space in an airplane and cost the freight forwarder the same to ship. If they were only charged by actual weight, then cushions could be shipped almost for free.

\text{Volumetric weight (kg)} = \frac{L \times W \times H \ (\text{cm})}{\text{divisor}}

The conversion factor is a commercial decision and not a physical constant; therefore one will find different factors on various websites without explanation for the differences.

Mode	Divisor (cm3/kg)	Equivalent density	Who uses it
Ocean LCL (W/M rule)	1,000	1,000 kg/m3	Container lines, NVOCCs, consolidators
Air freight, general cargo	6,000	167 kg/m3	IATA standard, most airlines
Courier and express	5,000	200 kg/m3	DHL, FedEx, UPS and similar
US domestic parcel	139 in3/lb	About 250 kg/m3	Ground parcel networks

Sea and air freight are subject to the same rules but with different constants.

This is a point worth highlighting separately because few transport sites explicitly mention it.

Sea freight uses the W/M rule and charges either by weight or volume, i.e. the greater of one cubic meter or 1,000 kg. Air freight uses dimensional weight divided by 6,000. These two practices are described as being independent of each other.

In fact there is only one rule. Divide a million by the conversion factor to get density in kg/m3. For airfreight it's 6,000 = 167. For courier services it's 5,000 = 200. The sea freight rule that 1 CBM equals 1 tonne is exactly the same as a conversion factor of 1,000.

\text{break-even density} \ \left(\text{kg}/\text{m}^3\right) = \frac{1{,}000{,}000}{\text{divisor}}

That's why this shipping calculator has only one number for the choice of shipping methods; whether it is sea freight, air freight or courier services and also with individual tariffs: It is always the same formula, just the position of the constants changes. If you understand that, then you can compare any two cost estimates in your head.

Which side of that line are you on?

Compare the density of your actual cargo with the critical density limit mentioned above.

\text{cargo density} = \frac{\text{gross weight (kg)}}{\text{volume } (\text{m}^3)}

If the density of your shipment is above this critical value then weight will be the determining factor. As the price is calculated based on actual weight, optimizing your packaging to save space will not change the billable amount. If the density of your shipment falls below this value then volume becomes the deciding factor. Every inch of air in your carton box will incur additional charges so better packaging can help you save money.

For our example carton: 700 / 4.8 = 146 kg/cbm. When compared to the critical value for courier services (200), the price is calculated based on volume. Also when compared to the critical value for ocean freight (1,000), the price is calculated based on volume but with a bigger difference. Only goods with a density of more than one tonne per cubic meter are charged by weight in ocean freight. This explains why ocean freight feels like a volume business while air freight feels more like a weight business.

Cargo	Rough density (kg/m3)	Billed by, at sea	Billed by, by air
Feather pillows, foam	30 to 60	Volume	Volume
Flat-pack furniture	120 to 200	Volume	Volume, marginally
Boxed apparel	150 to 250	Volume	Weight
Canned food	600 to 800	Volume	Weight
Tiles, stone, machinery	1,500 to 2,500	Weight	Weight

How many cubic meters can be loaded onto a transport container?

Ask five different warehouses and you'll get five different answers for the same 20-foot container: 33 cubic meters, 31.2, 32.8, 26 to 28, 25 to 28. It seems like a battle of facts, but it's not.

The larger numbers represent the geometric volume, i.e. length x width x height of interior measurements. The smaller numbers represent the same container value taking into account losses when loading. This includes cartons that cannot be stacked without gaps, required workspace, top space loss by pallets by 20 cm, padding material and reinforcement bands. Logistics companies typically use actual values which are slightly over the nominal volume of 80 percent. Moving companies plan with 90 percent and consider the rest as a safety reserve.

So the honest answer is the value obtained by applying a selected charge efficiency to the nominal volume, which is how this calculator works.

Container	Internal dimensions	Nominal	At 85%	Payload limit
20ft standard dry	5.90 x 2.35 x 2.39 m	33.2 m3	28.2 m3	28,200 kg
40ft standard dry	12.03 x 2.35 x 2.39 m	67.7 m3	57.5 m3	26,700 kg
40ft high cube	12.03 x 2.35 x 2.70 m	76.3 m3	64.9 m3	26,460 kg
45ft high cube	13.56 x 2.35 x 2.70 m	86.0 m3	73.1 m3	27,600 kg

As dimensions can vary by a few centimetres due to different manufacturers or the age of the container, these values should be considered as planning data. If a shipment is almost loaded up to its maximum capacity (less than one percent leeway), then the actual container should be checked.

Are you filling volume or exceeding weight?

A container has two capacities but most online calculators only model one of them.

A 20-foot container has a volume of about 33 cubic meters and a maximum load capacity of about 28.2 tons. Dividing the first by the second gives about 850 kg per cubic meter. Goods with a higher density than this value will fill the container in terms of weight before it is completely filled. Tiles, natural stone, liquids, batteries, machinery and high-density paper products reach their weight limit before the volume is full.

This is not just a problem for the shipping lines. The weight restrictions on roads at both ends of ocean freight are often more restrictive than the nominal capacity of the container itself. Even if a container has been legally loaded at the point of departure, it may not be able to be transported by truck at the destination. The resulting Container Matrix indicates which limit is reached first by the goods so that problems can be identified before booking and not just when arriving at the gate.

Shared freight or own container?

In shared transport, goods share a container with other goods and are charged only for the space actually occupied. With your own container, you pay a flat rate for the entire container, regardless of the volume actually used.

The critical point in most markets is around 15 cubic meters. If the volume is below that, a LCL will almost always be cheaper. Above that, the cost per cubic meter plus fixed charges for LCLs, unloading and container terminals exceed the flat rate of a full 20ft container. In addition, moving in a full container is faster, requires less handling, and avoids problems associated with customs clearance procedures at forwarders who offer LCLs.

You can calculate the break-even point yourself by dividing the flat rates for container freight by the unit price per tonne of bulk cargo. If the result is less than your own billing volume, choose the container. Open the "Costs" section at the top and enter the bulk cargo prices, then the calculation tool will calculate the billing volume.

Dimensions of mixed cartons:

This calculator only processes one type of package dimensions at a time, as the freight rates of forwarders are also structured according to this principle. For consolidated shipments, you calculate each dimension separately and then add up the cubic meter numbers.

Don't average the dimensions. If you average the three carton types' dimensions and then multiply by the total number, you will get a result that is different from the actual sum of volumes and usually smaller. This difference will eventually show up on your bill. Add volume and weight separately and compare these sums as billing weight for one shipment. Shippers do not apply W/M (weight per cubic meter) rule to individual cartons but to the whole shipment.

Cylinders, rolls and irregularly shaped goods:

Since shipping costs are based on the smallest cube that can contain your item, shippers generally round items up to the nearest square. The diameter is treated as both the width and height.

So a cylindrical drum with a diameter of 60 cm and a height of 90 cm is calculated as having a volume of 0.6 x 0.6 x 0.9 = 0.324 CBM, which will be different from the actual volume of the cylinder.

\pi \times (0.3\,\text{m})^2 \times 0.9\,\text{m} = 0.254\ \text{m}^3

This equates to a surcharge of 27% for the corners. There are also carriers that will accept actual volume on regular cylindrical goods so it is best to check ahead rather than jump to conclusions.

For really irregularly shaped items you will need to measure the longest, widest and highest points including handles, feet and overhangs and use those measurements. Even if a normally regular wooden box has a 10cm long pointed cut out this would be included in the overall length for calculation purposes.

For smaller goods - trucks and trailers:

The same calculation also applies to domestic transport and local deliveries, with only the capacity data being lower.

Trailer or body	Level load height	Approximate capacity
6ft x 4ft trailer	2 ft	1.4 m3
6ft x 4ft trailer	3 ft	2.0 m3
7ft x 4ft trailer	3 ft	2.4 m3
8ft x 5ft trailer	3 ft	3.4 m3
Long-wheelbase van	Internal	10 to 12 m3
7.5 tonne box truck	Internal	35 to 40 m3

Loose materials such as dirt, sand and gravel are often stacked higher than the horizontal plane so about a third should be added to the volume of the horizontal load. Always check axle weight limits before considering volume. A construction trailer filled with wet sand will often exceed its plate weight long before it is full.

Where are these values used in the end?

The cubic meter measurement is not just limited to quotes. It's used on packing lists and bills of lading, affects the calculation of freight class for domestic U.S. trucking, determines whether a consolidator will accept a reservation, and is a value that customs agents check if the declared volume doesn't match what they measure at the terminal.

At the terminal they will measure again. If a container is larger than stated on the manifest then the freight forwarder will re-calculate the freight based on their own measurements and charge an additional fee. Often this is not noticed until weeks later when the invoice arrives. It's cheaper to include pallets and all protruding parts and be honest about your measurements than to get a surcharge.

The values given here are estimates for planning purposes. Container dimensions may vary by manufacturer, and the conversion factor is set by each carrier and can be negotiable. Freight rates also change weekly. Check the conversion method and volume using the cost estimate before confirming a reservation.

Frequently asked questions

How to calculate transport CBM?: Multiply length, width and height all in meters then multiply by the number of pieces. A box with dimensions 50cm x 80cm x 60cm has a volume of 0.5 x 0.8 x 0.6 = 0.24 cubic metres, and twenty boxes would be 4.8 CBM. If you are using centimetres multiply the three values then divide by 1,000,000. For inches divide by 61,024 and for feet divide by 35.3147. Measure the outside dimensions of your shipment including pallets and overhangs as this is what the freight forwarder will be selling space for.
How many cubic meters can be loaded into a single 20ft or 40ft container?: Geometrically speaking there are standard containers with a volume of about 33 cubic meters for the 20-footers and about 67 cubic meters for the 40-footers. The actual load capacity however is between about 25 and 28 as well as between 54 and 58. This is because cartons cannot be stacked perfectly and working space is needed. The discrepancies in published values are due to these empty spaces. An identical 20-footer can be stated at one location with 33 CBM and another with 26 to 28, both of which could be correct. This calculator treats the two cases separately. First it calculates the nominal volume from the internal dimensions, then a user-defined loading efficiency factor is applied. For mixed loads of cartons a value of 85% can be used as a reasonable starting point. With regular palletized loads up to 90% can be reached while with irregularly shaped goods the figure can drop down to 70%.
What is volumetric weight and what conversion factor should I use?: The volumetric weight converts the volume occupied by a shipment into a weight for which the freight forwarder charges. It is calculated by multiplying the three dimensions in centimeters and dividing it by the conversion factor used by the freight forwarder. For general air cargo shipments according to IATA, 6,000 is used, which equates approximately 167 kg per cubic meter. Most courier services (including DHL) use 5,000, resulting in 200 kg per cubic meter. Sea freight charges either 1 cubic meter or 1,000 kg, whichever is higher. This corresponds to a conversion factor of 1,000. Check the numbers given on the quote before relying on any particular value as they are negotiable and may vary by route.
Do I pay for actual weight or volume?: You pay for the higher of both. The freight forwarder calls this "chargeable weight", while ocean shippers talk about whether the charge is based on weight or volume. To make it simple: think of it as density. Calculate the kilograms per cubic meter for your shipment and compare that to the break-even point for each mode of transport. If the density exceeds 167 kg per cubic meter, then air freight charges are calculated on a weight basis. If it is below that, then they charge based on volume. For ocean shipping, the break-even point is at 1,000 kg per cubic meter, so most shipments (except metals and liquids) will be charged by volume. This simple comparison determines whether or not re-packaging makes sense in terms of cost-effectiveness.
Are CBM and volume the same thing?: Yes. CBM is just a shipping abbreviation for cubic meter volume. One CBM equals one cubic meter, which is approximately 35.3147 cubic feet or 1,000 liters. The only difference between CBM in shipping and the term "volume" in math class is that CBM always refers to the minimum volume of a box that can contain the cargo, not necessarily the volume of the cargo itself. If you pack a bike into a wooden crate, it will be billed by the volume of the wooden crate.
How many kilograms are in one cubic meter?: This depends entirely on the mode of transport. This is an important point. In shipping industry 1 CBM equals to a weight of 1,000 kg. According to IATA rules 1:6000 the weight for air freight is about 167kg. With shippers like 1:5000 it's 200kg. These are not measurements of the cargo but pricing guidelines. So the same pallet can be charged by an airline with 400 kg while a shipping company might charge per loaded tonne at 2.4.
When should you switch from a collective load to your own container?: A general rule of thumb across the industry is about 15 cubic meters. If below that volume a LCL is usually cheaper. Above that, the sum of the cubic price for an LCL plus the handling and terminal charges often exceeds the flat rate for a 20ft container. You also get faster processing and avoid the risk of having to share a container with others. Use the table below to do your own calculations. Enter in the cost of an LCL, read off the calculated volume and compare it against a flat rate offer from other companies for a dedicated container.
How do I calculate the volume (cbm) of cylindrical or irregularly shaped packages?: You use the smallest possible rectangular shape that will fit around your item. For cylindrical objects carried upright, most shippers count the circle as a square and treat the diameter as both width and height. So a cylindrical barrel with a 60 cm diameter and a 90 cm height would be calculated at 0.6 x 0.6 x 0.9 = 0.324 CBM. However, some shippers will accept the actual volume of the cylinder, which is pi x radius x radius x length. The volume for that same barrel would be 0.254 CBM, so it's worth asking. For really irregularly shaped items you should measure the maximum length, width and height including any protruding parts.

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Disclaimer: This calculator is provided for general informational and educational purposes only. Our calculators are under active development, and results may be inaccurate, incomplete, or unsuitable for your situation. Always verify the figures independently and seek advice from a qualified professional before relying on them. We make no warranties and accept no liability for any loss or decision arising from use of this tool.

References

IATA — Air Cargo Tariffs and Rules (TACT)
The industry rulebook behind the 1:6000 volumetric divisor used for general air cargo, equivalent to 167 kg per cubic metre.
Wikipedia — Containerization (ISO 668 container standards)
Background on the ISO 668 series-1 container standard that fixes the external dimensions and maximum gross weights of 20ft, 40ft and 45ft boxes, from which the internal volumes and payload limits here are derived.
FedEx — Package weight and dimensions
A carrier's own statement of how dimensional weight is measured and billed on express parcels, the family of rules the 1:5000 divisor belongs to.
Wikipedia — Dimensional weight
Background on why carriers bill light, bulky freight by volume, and how the divisors differ between modes and regions.
Wikipedia — Intermodal container
Internal dimensions, tare weights and payload ratings for the standard dry and high-cube container types offered in this calculator.
UNCTAD — Review of Maritime Transport
Annual United Nations review of seaborne trade, containerisation and freight cost determinants.