Calculate carton volume in CBM
CBM means cubic metres: the space occupied by a box, not its weight or its shipping price. For rectangular cartons, multiply length, width and height. Convert the length units before calculating, or use the conversion below.
Litres = cm³ ÷ 1,000
CBM = cm³ ÷ 1,000,000
Total CBM = one carton’s CBM × carton count
Worked example
One 40 × 30 × 20 cm carton occupies 24 litres, or 0.024 m³. Ten identical cartons occupy 0.24 m³. Using inches instead converts through 2.54 cm per inch; a 12 × 12 × 12 inch cube is exactly one cubic foot.
Different sizes need separate calculations
Calculate each carton size separately, multiply by its quantity, then add the totals. For example, ten cartons at 0.024 m³ and four cartons at 0.012 m³ have a combined geometric volume of 0.288 m³. Entering an average side length can produce the wrong total because volume is a product of three measurements.
Volume does not guarantee a fit
Empty space between stacked cartons, pallets, overhang, load restrictions and the loading arrangement can increase the space a shipment actually needs. A box may also have enough total volume for a product but the wrong shape. Use the carton fit calculator when checking rectangular items inside a box.
Common questions
Is CBM the same as dimensional weight?
No. CBM describes volume. Dimensional weight applies a service-specific divisor to volume to produce a weight figure. Use the dimensional weight tool to make that comparison.
Can I use inner dimensions?
Use inner dimensions to estimate usable capacity, but outer dimensions to describe a shipment. The formula works for either; the meaning changes with the measurements you enter.
Does this calculate pallet space?
No. It totals rectangular carton volume only. Pallet thickness, arrangement, stacking gaps and transport restrictions are not modelled.