(1) calculated by weight (Weight). According to weight, it is widely used in today's international trade. For example, many agricultural and sideline products, mineral products and manufactured goods are all measured by weight. The units measured by weight are metric tons, long tons, short tons, kilograms, grams, ounces and so on.

(2) according to quantity (Number), most industrial manufactured goods, especially consumer goods, light industrial products, mechanical products and a special local product, are used to buy and sell according to quantity.

(3) according to the length (Length), meters, feet, yards and other units of length are usually used in the trade of metal ropes, silk, cloth and so on.

(4) calculated by area (Area). In the trade of glass, carpet and other commodities, it is customary to use area as a unit of measurement, commonly used in square meters, square feet, square yards and so on.

(5) calculated by volume (Volume). The volume of products sold by volume is limited. It is superior to wood, natural gas and chemical gas. The unit of measurement belongs to this area. There are cubic meters, cubic feet, cubic yards, and so on.

(6) by volume (Capacity), all kinds of cereals and liquid goods are often measured by volume. In the United States, Bushel is used as the unit of measurement for all kinds of cereals. However, the weight of bushels is different from that of grains. For example, the seeds of linseed are 56 pounds per oat, 32 pounds of oats, 60 pounds of soybeans and wheat, and liters of gallons, and gallons are used for sprinkling and measuring oil products.

According to the unit of weight, according to the general

      A.凈重

Net weight (Net Weight) refers to the weight of the commodity itself. According to international practice, if there is no other provision for the calculation of weight in the contract, the net weight should be measured.

Some goods can be weighed after being packed, and the weight is gross.

For low value commodities, the gross weight can be measured in the contract, that is, the so-called "Gross for Net".

If net weight is to be calculated, the weight of the package must be deducted from gross weight, that is, tare weight.

There are several ways of calculating tare:

      · 實(shí)際皮重。即稱量每件包裝物的重量。 

      · 平均度重。在包裝物比較劃一的情況下，可從全部商品中抽取一定件數(shù)的包裝物，加以稱量，求出平均每件包裝物的重量。 

      · 習(xí)慣皮重。適用于規(guī)范化的包裝方式。包裝的重量已為人所共知，無需稱量。 

      · 約定皮重。雙方事先約定的包裝重量。

      B. 公量

In order to accurately calculate the weight of such goods, such as wool, raw silk and cotton, which are not stable in dry moisture content, Conditoned weight method is commonly used internationally, that is, determining the actual moisture regain (moisture content) of the commodity, so as to calculate the weight of the goods and then convert them into the weight of the regain.

The formula is as follows:

The weight is [the actual weight of the goods / (10 actual moisture regain)]X (10 regrescent rate) = the net weight of the goods is X (10 regrescent moisture regain).

      C.理論重量 

For some commodities with fixed size, the weight of each piece is basically the same. The total weight can be calculated from the number of items.

That is, the so-called Theoretical Weight to facilitate the pfer of goods between the seller and the buyer.

Editor: vivi