Convert from fanega to labor

Unit Definition (fanega)
The Fanega is a traditional unit of land area in Spain and in some Latin American countries. The unit originated as the amount of land that could be planted with a fanega (a Spanish unit of volume) of seed. It varied considerably from one area to another. In 1801 it was standardized in Spain as the area of a square 96 varas (80.2 meters) on a side; this comes to 0.643 hectare (1.59 acres). After the introduction of the metric system it became customary to refer to an area 80 meters square as a fanega. This unit is not legal but is still used informally in some parts of Spain. The Central American manzana is a counterpart of this traditional Spanish unit.

Unit Definition (labor)
The labor is a traditional unit of area in Latin American countries. The labor is equal to the area of a square 1000 varas on a side, or 0.04 legua. Using the Texas standard for the vara (33 1/3 inches), this is equivalent to 177.136 acres or 71.685 hectares. The word labor means work in Spanish, as it does in English. As a unit it represents the area that could be cultivated by a single farmer, somewhat like the old English hide.