Abstract: The custody transfer metering and adjustment of products for railroad tanker is one of the most important links in the chain of trade of petroleum products, and the metering accuracy of products will be directly related to the profits of petroleum enterprises.The problems on metering error of railroad tanker for products with different viscosities and adjustment induced from the metering error are analyzed.This paper lists the practical equations, which can be used to accurately calculate the actual loading volume adjustment volume.With the equations, the economic loss can be effectively reduced.