Container Loading Calculator: 20GP, 40GP & 40HQ CBM Planner

By raw internal geometry, a 20GP holds about 33 CBM, a 40GP about 67 CBM, and a 40HQ about 76 CBM. In practice you rarely reach those figures. Planning at roughly 25 to 28 CBM for a 20GP, 55 to 58 for a 40GP and 65 to 68 for a 40HQ is realistic for palletised or cartoned cargo, because boxes do not divide evenly into the container and space is lost to bracing.

It depends entirely on the carton size, not just the volume. Divide each container dimension by the corresponding carton dimension, round each down, then multiply. A 60 x 40 x 35 cm carton gives roughly 20 along the length, 5 across the width and 7 layers high in a 40HQ, so about 700 cartons before allowing for clearance. The 3D tool on this page tests every rotation and shows the real stacked layout.

Because the cargo density exceeds the container design density. A 40HQ has about 76 CBM of space but only 26,500 kg of payload, which works out to roughly 350 kg per CBM. Anything denser than that (tiles, liquids, machinery, metal parts) hits the weight limit while the container still looks half empty. That is normal, and the correct answer is usually to book more 20GP units rather than fewer 40-foot units.

One 40GP gives roughly double the volume of a 20GP but slightly less payload than two 20GPs combined, and it is almost always cheaper per CBM than two 20GPs. Choose two 20GPs when the cargo is heavy and weight limited, or when destination road regulations cap the weight per truck. Choose a 40GP or 40HQ when the cargo is light and volume limited.

Identical length and width, but a 40HQ is about 30 cm taller inside, giving roughly 9 extra CBM. If your cargo stacks in layers, a 40HQ often fits one more layer for a small freight premium, which is usually the cheapest capacity you can buy. It only helps if the extra height translates into a whole additional layer.

The rear door opening is smaller than the internal cross-section, typically about 233 cm wide and 258 cm high on a 40HQ versus 235 cm and 269 cm inside. A tall crate or a wide machine can be geometrically fine inside the container yet impossible to get through the doorway. Always check the door dimensions for any single piece over about 200 cm in any direction.

Well-planned cartoned cargo typically achieves 80 to 90 percent volume utilization. Palletised cargo usually lands around 65 to 80 percent, because the pallet deck itself consumes height and the pallet footprint rarely tiles the container floor perfectly. Anything above 90 percent normally requires hand-stacked loose cartons and a carton size chosen to divide evenly into the container.

A 20GP holds about 10 standard 120 x 100 cm pallets or 11 Euro pallets in a single tier. A 40GP or 40HQ holds about 20 to 21 standard pallets or 24 to 25 Euro pallets. Double stacking can increase these figures if the cargo and pallet height allow it and the lower pallets can carry the load.

As a rough rule, below about 15 CBM an LCL booking usually costs less than a full 20GP, and above that FCL tends to win on both price per CBM and transit reliability. Compare actual quotes: LCL carries per-shipment handling, deconsolidation and destination charges that scale poorly, and it involves an extra handling step where damage risk is higher.

Use an open top when the cargo is too tall or too awkward to pass through the rear doors and must be craned in from above. Note that over-height cargo on an open top attracts extra charges, needs carrier approval, and requires proper lashing and a tarpaulin. If the cargo fits through the door, a standard container is always cheaper and simpler.