Convert from ngarn to fanega

Unit Definition (ngarn)
The ngarn is a unit of land area in Thailand. The ngarn equals 1/4 rai, 100 talangwah (tw), or exactly 400 square meters (478.396 square yards or just under 0.1 acre).

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.