Container load calculator: cartons, CBM and container fit

It depends on how the t-shirts are folded and packed, so work it out from your carton, not from a rule of thumb. Take the outer size of one packed carton and the pieces in it, count how many whole cartons fit along, across and up the container, and multiply by the pieces per carton. As an illustration only, take the packing list template’s example carton of 60 × 40 × 20 cm holding 24 folded t-shirts. Maersk gives the inside of its 20-foot standard container as 5,896 × 2,350 × 2,393 mm, which takes 9 cartons along, 5 across and 11 high with every carton upright: 495 cartons, or 11,880 t-shirts. By volume alone, at our assumed packing efficiency of 85%, the same carton gives 587 cartons, or 14,088 t-shirts, but that is more than whole cartons of this size can reach standing upright: turning the last rows adds a few to the stacked count, so treat the volume figure as an upper guess, not a target. Weight does not limit it: 495 cartons at 6.9 kg are 3,415.5 kg against a payload of 28,200 kg. Heavier fabric, hangers or retail packaging change the carton, so enter your own figures and ask your forwarder for a load plan before you book. It is an example, not a promise of what your order will fit.

When the shared-container charges for your volume add up to more than the all-in price of a 20-foot container, and the break-even point comes from your own two quotes, not from a fixed rule. Less-than-container-load (LCL) cargo shares a box with other shippers’ goods and is paid mainly by the cubic metre; it is consolidated at origin and split again at destination, which adds days and some risk of damage. A full container (FCL) is one price for the box, however much you put in it. Divide the all-in 20ft quote by the all-in LCL price per cubic metre: above that volume, the full container costs less. The calculator gives you the volume to compare. In its opening example, 209 cartons of 60 × 40 × 20 cm come to 10.03 CBM, about 30% of a 20-foot container’s internal volume. Compare all-in prices, with the charges at both ends, and ask your forwarder for both quotes on the same sailing dates, because rates move with the season and the route.

Chargeable weight is the weight an airline bills: the greater of the shipment’s actual gross weight and its volumetric weight. Volumetric weight is length × width × height in centimetres divided by 6,000, the divisor Maersk describes as the industry standard set by IATA, the airlines’ trade association. Clothing is light for its size, so volume usually decides. In the calculator’s opening example, one carton of 60 × 40 × 20 cm has a volumetric weight of 8 kg against an actual 6.9 kg, so 209 cartons are charged as 1,672 kg rather than 1,442.1 kg, about 16% more. Not every carrier uses 6,000: some airlines divide by 5,000, and express couriers such as DHL do too, which makes the same carton 9.6 kg. To bring the bill down, cut the empty space: a carton sized to the folded garments, or more pieces in each carton within the weight your buyer allows, lowers the volumetric weight directly. Check which divisor your forwarder’s quote uses before you compare prices.

Because there are two fair ways to estimate a load, and a real load usually sits between them. The stacked count is geometry: how many whole cartons fit along the length, across the width and up to the load line, with every carton turned the same way, using the internal dimensions Maersk publishes. It is the safer of the two figures, and a loader can often add a few cartons to it by turning the last rows to fill a gap. The volume estimate divides the container’s internal volume, reduced by a packing efficiency, by the carton’s volume. The efficiency is our assumption, 85% unless you change it, because cartons never fill a box completely: there are gaps at the walls and the roof, full cartons bulge, and the loader needs room to get the last ones in. It is not a published standard. For the opening example in a 20-foot container, the counts are 495 stacked and 587 by volume. The calculator judges whether your order fits on the stacked count and says “possibly” when only the volume estimate holds it. Before you book, ask your forwarder for a load plan.

Rarely, because garments fill a container’s space long before its weight limit, but check it for dense goods. Maersk’s specification sheet gives a maximum payload of 28,200 kg for its 20-foot standard container, 28,800 kg for the 40-foot and 28,620 kg for the 40-foot high cube. In the calculator’s opening example, a full 20-foot load of 495 cartons at 6.9 kg weighs 3,415.5 kg, about 12% of the payload. Dense goods such as heavy denim, towels or workwear in large cartons come closer, so the calculator caps every count at the payload and says when weight, not space, is the limit. Two cautions. The payload on the door plate of the box you are given can differ from the published figure. And the weight a truck or train may carry is set by the rules of the country it travels through, which can be lower than what the container is built for; your forwarder knows the limit on your route. Weigh packed cartons rather than estimating, because the gross weight on the packing list is compared with the scale.