Convert from fanega to mu

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 (mu)
The mu is a traditional unit of land area in China. The traditional mu is about 675 square meters or 800 square yards. However, the colonial customs authorities used a larger mu equal to 8273.75 square feet, 919.3 square yards, or 768.65 square meters. In modern China, the mu is often reckoned to be exactly 1/15 hectare, which is 666.667 square meters or 797.327 square yards.