Choose a container, enter the size of one carton and, if you know it, its weight. The calculator places the cartons the way a loader would, block by block, and tells you how many fit by space, how many the payload allows, and so how many go in each container. Add the number of cartons you are shipping to see how many containers you need. With a weight, you also get the verified gross mass (VGM) that has to be declared before a container goes on a ship.
Choose the container
The four listed types are dry containers, with the typical inside measurements, tare and maximum gross mass published by the carrier Ocean Network Express. Yours may differ by a few centimetres or kilograms: type the tare marked on its door and the maximum gross mass on its CSC safety approval plate to use them instead. For a reefer, an open top or any other container, choose Other and enter its inside length, width and height, its maximum gross mass and its tare.
Describe the cartons
Measure one carton in centimetres. Upright keeps the top of the carton up but lets it turn on its base; Any side lets the calculator lay it on its side too. If the cartons can only be stacked so high, enter the most cartons in one stack: 1 for pallets that cannot be double-stacked. Pallets, dunnage and lashing are counted once per container, in the weight loaded and in the VGM.
Read the result
The calculator first fills a main block with cartons all placed the same way, then the rest of the length and the rest of the width with cartons turned the best way. Each block is shown in the workings, so you can check it with a tape measure. The number per container is the smaller of what fits and what the payload allows: cartons are rounded down and containers rounded up. Measurements are used as typed, to 0.01 cm; anything finer is rounded up for a carton and down for an Other container, so a carton that does not fit is never counted. Volumes are rounded to the litre (0.001 m³) and shares to 0.1 of a percentage point, to the nearest. With several containers, the volume, weight and VGM are those of a full one; a note gives the VGM of the last. For a listed type, a carton too tall or too wide to pass the door is not placed that way.
By space: for each block, (length ÷ carton length) × (width ÷ carton width) × (height ÷ carton height), each rounded down, then the blocks added up.
By weight: (maximum gross mass − tare − pallets and dunnage) ÷ weight of one carton, rounded down.
Per container: the smaller of the two. Containers = cartons to ship ÷ cartons per container, rounded up.
VGM = cartons + pallets, dunnage and lashing + tare (SOLAS method 2).
Example: 500 cartons of 60 × 40 × 50 cm in 20ft containers
Inside, a 20ft standard container measures 589.8 × 235 × 239 cm. Turned so that their 40 cm side runs along the container, 14 × 3 cartons cover the floor and 4 stack up: 168 cartons. The 55 cm left across the width takes a row of 9 cartons the other way round, 4 high: 36 more, so 204 fit. At 18 kg each, the payload of 28,330 kg would allow 1,573, so space is the limit. 500 cartons need 3 containers, the last holding 92. A full container carries 24.48 m³ of cartons, 73.9% of its volume, and 3,672 kg; with the typical tare of 2,150 kg, its VGM is 5,822 kg, which the MCA would check to within ±500 kg.
