Puerto Rican units of measurement

Several units of measurements are used in Puerto Rico. The units of measure in use in Puerto Rico are based on the United States customary units with two major exceptions: roadway distance signs are measured in kilometers and gasoline is sold by the liter.

System before US customary units
Several units were used before the US takeover in 1898. These units were older Spanish units.

Area
Several units were used to measure area. Among them were the cuerda and the caballería.

Cuerda
In Puerto Rico, a cuerda is a traditional unit of land area nearly equivalent to 3,930 square meters, or 4,700 square yards, 0.971 acre, or 0.393 hectare (ha). The precise conversion is 1 cuerda = 3,930.395625 m2. The term "Spanish acre" instead has been used sometimes by mainlanders. A cuerda and an acre have often been treated as equal because they are nearly the same size. It continues to be an official unit of land measure in Puerto Rico today (2019).

Caballería
This was a unit of land measurement in the Spanish Viceroyalties in the Americas during the times of the Spanish Empire in the 16th through 19th centuries Puerto Rico. Widely used then, it was equivalent to 78.58 ha. This unit of measure is now (2019) obsolete.