The United States is now the only industrialized country in the world that does not use the metric system as its predominant system of measurement. But the study found that measurement in the United States was already based on metric units in many areas. Studies says that metric system was in the best interests of the nation, particularly in view of the importance of foreign trade. Since most of the nation follow metric system, trade with United States is really hard. Business and trade cannot be run properly with the customary system. Nation who don't follow customary system found it hard to convert to customary units. Since there is a huge range of difference between customary units and metric units, business conversion and industrial growth decreased rapidly. But adult who may or may not receive any education about metric system will find it more challenging than customary units in which meters will be used instead of yards, liters instead of quarts and kilogram instead of pound. It is said that wine, liquors and many soft drink companies use a metric bottle for packaging. General motors and tire manufactures are also based on metric system. But every environment did not accept this metric system like housing industry and railroads. There is a need to change U.S to the metric system in order to sustain its trade and business. United Nation is one of those nations who follow customary system. Even though US don't follow the metric system, the pressure and inconvenience caused by the customary system is making the people to use the metric system. In schools, both teachers and students found it more easy and understandable than customary practice. Many people says that USA is still practicing customary system in order to keep the country's patriotic feeling. They said that customary measures are native to Americans. But most scientists and engineers argue for metrication. They says that continued use of customary measure will keep US i