In international trade, air and sea freight services are the two most common shipping methods. Certainly, express delivery is another option. The best way to learn the price of express delivery is to request express companies since every company charges by different rates. As for the freightage of air and sea shipping services, the amount of volume and weight of the goods are involved. There is a general principle which is when the amount of volume is bigger than that of weight, and then the freightage will be worked out by the volume, vice versa. It is can’t be determined by eyeballing, but by converting with a world-accepted formula. Especially when Receiving a shipment of huge volume and heavy weight goods（ex. Plastic sheet, tableware, notebook, and so on）, we have to carefully do the math. The polystyrene products, the amount of volume definitely is greater than that of the weight, which means the cuft should be calculated precisely. As for machinery or metal products, on the other hand, the amount of weight is usually greater than that of the cuft, which only need to charge freightage by the actual weight.

By contrast, the freightage of sea shipping service is less disagreement because it always be charged by volume. The differences of freightage are few overall though sometimes the amount of weight is greater than that of volume. The only thing must be concerned is the weight of the goods should be less than the weight limitations of the container when the goods is obviously seen as a heavy weight object.

For air cargo service, the cuft and weight are decisive parts in freightage. In most cases, the freightage is determined by the weigh of the goods. But in few cases like delivering polystyrene sheets, for example, the weight is 20 kg only, but might occupy the most space of cargo compartment. It is unprofitable to air shipping companies if they calculate the freightage of polystyrene sheets by weight. However, the shipping companies will choose the more profitable calculation between cuft and weight. As follow is the conversion between cuft and weight.

“As follow is the international conversion formula of cuft weight：
length x width X high(cm) / 6000 =cuft weight (kg)“

100 pieces of polystyrene sheet weigh 20 Kg, and the total volume is 150cm X 100cm X50 cm(length x width X high) the conversion into cuft is 150 x 100 x 50 x 0.0000353 = 26.48 cuft. (Cuft = Cubic Feet)