Quantitative appraisal An appraisal that proves the actual quantity of a commodity。The commodity inspection authorities shall, on the basis of the application of the foreign trade parties concerned, check and count the actual quantities of import and export commodities in accordance with the invoice, packing list or measurement list, and issue the certificate of quantity appraisal for the buyers and sellers to use as the basis for commodity quantity handover, settlement, claims and claims settlement。The quantity of goods is one of the important conditions in international trade contracts。

The quantity of commodities exchanged in international trade can be expressed by weight, volume, length, area, number, number, etc. Due to the different varieties and properties of commodities, the units and methods of measurement adopted by them are also different。通常，Bulk commodities are expressed in units of weight (tons)，Wood is expressed as a unit of volume (cubic meter)，Liquid commodities such as oil are expressed in units of weight (tons) or in units of volume (gallons)，Textiles are expressed in units of length (meters)，Leather is expressed in area units (square meters)，Clothing is represented by the number of pieces，Mechanical and electrical products are represented by numbers。According to international practice, if the quantity of the goods delivered by the seller is less than that stipulated in the contract, the buyer has the right to claim compensation or reject the goods。Therefore, the quantitative identification of commodities is directly related to the economic rights and interests of the parties concerned in the contract。The difference in the quantity delivered shall be made up in full by the amount of the quantity of the goods in excess or short according to the provisions of the overshipment clause, which is called "claim" and "claim settlement".。

In the international trade goods, the use of weight measurement of a lot of goods, weight calculation methods are gross weight, net weight, gross as net, weight, theoretical weight and so on。

Gross weight is the weight of the product itself plus the weight of the package and net weight is the actual weight of the product.The weight of the package is not included。In international trade, most goods measured by weight are priced by net weight。Some goods because the packaging itself is inconvenient to measure separately or because the packaging and the price of the goods are similar, can be measured by gross weight, which is habitually called "gross as net".。The calculation method of net weight is to subtract tare (packaging weight) from gross weight, tare has actual tare, average tare, customary tare, and agreed tare。The common quantity refers to the weight obtained by using scientific methods to remove the water in the commodity, coupled with the standard water content, which is suitable for commodities with high economic value and extremely unstable water content, such as raw silk and wool。Some products, such as tinplate, steel plate, etc., have fixed specifications and dimensions, and the weight is roughly the same, which can be calculated according to the number of sheets or pieces, called theoretical weight。