The Thai real property industry has a unique way of measuring land. In practice, there are three major land measurements used: the Tarang Wah, the Rai and the Ngan. The use of the metric system in the country is limited only to certain real properties such as buildings. In purchasing real property, it is important for every purchaser to understand that measurements such as a Ngan determine the prices of real properties as land prices are usually made on a per-Ngan basis. A Ngan measures approximately 100 Tarang Wah or 400 square meters. Therefore, it is important for every purchaser to know the proper measure of a Ngan in order not to be fooled by unscrupulous sellers.