The best direction for a master bedroom in the United States is typically the north or south. This recommendation is based on several factors, including natural light, privacy, and energy efficiency. According to the U.S. Department of Energy, orienting a bedroom to the north or south can maximize natural light and reduce the need for artificial lighting, which in turn can lower energy bills. Additionally, these directions can provide more privacy from neighbors and minimize exposure to intense sunlight, which can lead to excessive heat and glare. Studies have shown that rooms facing north tend to have more consistent temperatures throughout the year, which can contribute to a more comfortable sleeping environment.