How CBM is calculated
Convert every package dimension to metres, multiply length by width by height, then multiply by quantity. Sum the result across all package types to get the total shipment volume in cubic metres.
Sea freight chargeable weight rule
LCL ocean carriers use a 1:1000 ratio between cubic metres and kilograms. If your shipment is dense, gross weight wins; if it is light and bulky, volume wins. The calculator reports whichever is higher.
Air freight volumetric weight formula
IATA's standard divisor for general cargo is 6000. Airlines compare volumetric weight against gross weight and charge on the higher figure — the chargeable weight.
Working with cm vs inches
The calculator accepts either unit and converts to centimetres internally (1 inch = 2.54 cm). Weight is normalised to kilograms (1 lb = 0.45359237 kg) before any freight math is applied.
Who uses this calculator
- Freight forwarders quoting LCL and air consolidations.
- Exporters and importers preparing packing lists.
- E-commerce sellers estimating international shipping costs.
- Warehouse and 3PL teams validating carrier invoices.
Frequently asked questions
What is CBM in shipping?
CBM stands for Cubic Meter — the volume of a package measured in metres. It is calculated by multiplying length, width and height in metres (L × W × H).
How is sea freight chargeable weight calculated?
Ocean carriers compare gross weight to volume using the rule 1 CBM = 1000 kg. The chargeable weight is whichever is higher: total gross weight in kg or total CBM × 1000.
What is the air freight volumetric weight formula?
The international air freight divisor is 6000 for centimetres. Volumetric weight (kg) = (L × W × H in cm) ÷ 6000, multiplied by quantity.
Which weight will the airline charge?
Airlines charge the higher of gross weight and volumetric weight. Bulky, light cargo is billed by volume; dense cargo is billed by actual weight.
Can I mix multiple package types?
Yes. Use Add Row to enter each package type with its own dimensions, weight and quantity. Totals update automatically across all rows.
Does the calculator support inches and pounds?
Yes. Toggle dimensions between cm and inches, and weight between kg and lb. All conversions to metric happen automatically before the freight math runs.
Related guide
Read How to Calculate Chargeable Weight for Air and Sea Freight for the full methodology, divisors, and worked examples.