CBM Calculator: Chargeable Weight and Dimensional Weight for Air and LCL

Chargeable weight: the number your rate is multiplied by

Aircraft and containers run out of space long before they run out of lift. A pallet of pillows takes the same slot as a pallet of ball bearings, so carriers charge on whichever measure, weight or space, costs them more. That figure is the chargeable weight, and your rate per kilo is multiplied by it.

You need three inputs for each carton size: the outside dimensions of the packed piece (including the pallet if the goods ship palletized), the number of pieces, and the gross weight per piece. Carriers bill gross weight, not the net weight of the goods, so packaging, pallets, dunnage and shrink wrap all count.

Air freight: volumetric weight at 1:6000

General air cargo converts volume to weight at 6,000 cubic centimeters per kilogram, so one cubic meter counts as about 167 kg. For each piece, multiply length × width × height in centimeters and divide by 6,000 to get its volumetric weight in kilograms.

Express and courier services usually use a 5,000 divisor instead. That counts a cubic meter as 200 kg, so the same light carton costs more. Switch the divisor in the calculator to compare. Either way, the airline compares total volumetric weight with total actual gross weight and bills the higher one, normally rounded up to the next half kilo.

A quick rule: at the 6,000 divisor, cargo lighter than about 167 kg per cubic meter bills on volume, and denser cargo bills on actual weight. The calculator shows your loaded density, so you can see which side of that line you are on and whether a smaller carton would lower the bill.

Dimensional (DIM) weight in inches and pounds

US carriers state the same rule in inches and pounds and call it dimensional, or DIM, weight. Multiply length × width × height in inches and divide by the DIM factor to get pounds. For air freight the factor is 166 cubic inches per pound, which is the 1:6000 rule converted to imperial units; express and parcel services such as UPS and FedEx use 139 on their daily rates, the imperial form of 1:5000.

A carton of 40 × 30 × 24 inches has 28,800 cubic inches, so its DIM weight is 28,800 ÷ 166 = 173.5, billed as 174 lb. If the carton weighs 90 lb on the scale, it is billed at 174 lb; if it weighs 210 lb, it is billed at 210 lb. Weights in pounds are rounded up to the next whole pound.

The calculator shows the DIM weight and chargeable weight in pounds next to the kilogram figures whichever units you enter, so you can check a US quote stated in pounds against a foreign one stated in kilos.

Ocean LCL: revenue tons and the W/M rule

LCL (less than container load) shipments are billed per revenue ton on a W/M basis, short for "weight or measurement". One revenue ton is the greater of one cubic meter and one metric ton (1,000 kg). A 3 CBM shipment weighing 1,800 kg bills on 3 revenue tons; the same 3 CBM weighing 4,200 kg bills on 4.2.

So for ocean LCL the break-even density is 1,000 kg per cubic meter, six times the air freight threshold. Most consumer goods, furniture and textiles bill on measurement. Stone, tiles, machinery parts and liquids often bill on weight. Consolidators also charge a minimum, typically one revenue ton, so a very small shipment pays as if it were a full cubic meter.

Once a shipment grows past roughly 13–15 CBM, get a price for a 20′ container as well as LCL. A full container is priced per box rather than per cubic meter, and it goes through less handling.

FCL: chargeable weight does not apply

A full container load (FCL) is priced per container, not per kilo or per cubic meter. What matters instead is whether your cargo fits in the box and stays under its payload limit; the container load calculator checks both. Watch road weight limits at both ends too, since they often cap the load before the container’s own payload does.

Measure what ships, not the spec sheet

Measure the outer bulge, not the design dimension. Tightly packed cartons, shrink-wrapped pallets and anything strapped to a skid measure larger than the spec sheet says. The airline or CFS (container freight station) measures what actually arrives, commonly with a dimensioning scanner that rounds each side up to the next centimeter.

For palletized air cargo, the pallet counts in both volume and gross weight. A standard wooden pallet adds roughly 15–25 kg and around 12–15 cm of height before the first carton goes on. Any overhang beyond the pallet footprint is measured too.

If a re-measure at origin comes back larger than your booking, the difference shows up on the invoice. Sending accurate dimensions with your booking request is the cheapest way to avoid that.