Metrication in Peru

Peru adopted the metric system in 1862. Before, the Spanish system of measures was used. 
History.
In 1862 the Peruvian government decreed the metric system to be official in Peru. However, several years later the old measurements were still used. In 1869 a new law made the metric system compulsory.
In 1875 Peru adhered to the International Bureau of Weights and Measures in Sèvres, France.
The most current law regarding the measuring system is Law 23560, of 1982.