Puerto Rican units of measurement
Several units of measurements are used in Puerto Rico. The metric system has been compulsory since 1860 in Puerto Rico. One notable exception are public roadway speed limits: whereas distances are shown in the metric system (kilometers) speed limits are posted in the United States customary units (miles per hour).
System before metric system
Several units were used before metric adoption. These units were older Spanish units.
One cuerda is equal to 2250 vara2(1572 m2). It continues to be an official unit of land measure in Puerto Rico today (2019).
- Speed limits are posted in the US customary units because, presumably, this way drivers can correlate them to the speedometers in their automobiles which show speeds in miles per hour only or as the most prominent scale on speedometers.
- Washburn, E.W. (1926). International Critical Tables of Numerical Data, Physics, Chemistry and Technology. 1. New York: McGraw-Hil Book Company, Inc. p. 10. Retrieved 8 February 2015.
- Units - Cuerda. Sizes.com. Puerto Rico Act 135, section 4 (page 100), 1913–14, as amended by Act No. 3, 1913–14: A cuerda, quote: "a unit of land area, approximately 3,930 square meters (approximately 0.971 acres)...In land measurements and records, the measurement by cuerda customarily used in Porto [sic] Rico...equivalent to 3,930.395625 square meters..."
- Eli Oquendo Rodriguez. Los Barrios de Ponce: Noticias y Microhistorias de Ocho Comunidades Ponceñas en el Tiempo: Siglos XVI al XIX.. Lajas, Puerto Rico: Editorial Akelarre. 2019. pp. 183-185.
- Caballería (Spanish). Sizes.com Accessed 22 October 2019.
- Eli Oquendo Rodriguez. Los Barrios de Ponce: Noticias y Microhistorias de Ocho Comunidades Ponceñas en el Tiempo: Siglos XVI al XIX.. Lajas, Puerto Rico: Editorial Akelarre. 2019. pp. 183-184.