Convert from ngarn to square kilometer

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 (square kilometer)
The square kilometer is a common metric unit of area. One square kilometer equals 100 hectares, 10E6 square meters, approximately 247.105 acres, or approximately 0.386 102 square mile.