Convert from rai to cover

Unit Definition (rai)
The rai is a traditional unit of land area in Thailand. The rai is now considered to equal exactly 1600 square meters, which is 0.16 hectare or approximately 0.3954 acre. The rai is divided into 4 ngan. The unit is called the hai in northern Thailand and the lai in Laos. The word means "field," that is, an upland field rather than a rice paddy.

Unit Definition (cover)
The Cover is a traditional Welsh unit of area, standardized in the British system to be exactly 2/3 acre (about 0.2698 hectare). The word is an Anglicized version of the Welsh name cyfair for the unit.