Carton calculator for CBM & container loading
Enter your product dimensions and packing layout to instantly calculate master carton size, CBM, volumetric and chargeable weight, space utilization, and how many cartons fit in a 20ft, 40ft, or 40ft High Cube container.
Product & packing
▸Advanced settings
Usable volume and payload vary by carrier and stacking. Adjust to match your forwarder's figures.
Carton specification
| Container | Cartons | Total units | Total weight (kg) |
|---|
Containers needed — 20GP: — · 40GP: — · 40HQ: —
Container figures are planning estimates based on usable volume and weight limits. Actual loading depends on stacking pattern, pallet use, and load distribution — always confirm with a load plan.
How the carton calculator works
A carton calculator turns a single product's dimensions and packing layout into the numbers you need to quote freight and plan shipments: master carton size, cubic volume (CBM), shipping weight, and container capacity.
This tool offers three modes. Known carton is for when your factory has already provided the carton size and case pack — enter them to compute CBM, weights, and container loading. By layout builds the carton for you from the product size and how many units sit along the length, width, and height. Optimize finds the packing arrangement that fits the most units inside a maximum carton size, testing every product orientation.
Key formulas
CBM = L × W × H (in metres)
= L_cm × W_cm × H_cm ÷ 1,000,000
Vol. weight (kg) = L_cm × W_cm × H_cm ÷ divisor
Chargeable = max( gross weight , vol. weight )
Utilization = (product vol × units) ÷ carton vol
Shipping terms glossary
- Master carton (case pack)
- The outer shipping box that holds a fixed number of retail units. Its size and pack quantity define the "carton spec."
- CBM
- Cubic metres — the volume of a carton, used to price ocean freight (LCL) and calculate container fill.
- Volumetric weight
- A weight derived from volume so carriers can charge for bulky-but-light shipments.
- Chargeable weight
- The greater of actual gross weight and volumetric weight — what you are actually billed for.
- Gross vs net weight
- Net weight is the product alone; gross weight adds packaging and the empty carton (tare).
- Tare weight
- The weight of the empty master carton and dunnage, before any product is added.
- 20GP / 40GP / 40HQ
- Standard dry containers: 20-foot, 40-foot, and 40-foot High Cube (taller, more volume).
- Space utilization
- How much of the carton's internal volume is filled by product versus void space.
Container capacity reference
| Container | Internal (L×W×H, m) | Nominal volume | Usable volume | Max payload |
|---|---|---|---|---|
| 20GP | 5.90 × 2.35 × 2.39 | ≈ 33 m³ | ≈ 25–28 m³ | ≈ 21,800 kg |
| 40GP | 12.03 × 2.35 × 2.39 | ≈ 67 m³ | ≈ 55–58 m³ | ≈ 26,500 kg |
| 40HQ | 12.03 × 2.35 × 2.69 | ≈ 76 m³ | ≈ 65–68 m³ | ≈ 26,000 kg |
Nominal volume is the full internal cube; usable volume accounts for the void space left by real-world stacking. Maximum payload varies by carrier, route, and road-weight limits.
Frequently asked questions
What is CBM and how do you calculate it?
L × W × H by 1,000,000. For example, a 60 × 40 × 40 cm carton is 96,000 cm³, or 0.096 CBM.How do you calculate volumetric (dimensional) weight?
L × W × H in centimetres divided by a divisor. The common divisor is 6000 for express and courier shipments, and 5000 for air freight. It lets carriers charge fairly for bulky but lightweight cargo.