Bangkok,[a] officially known in Thai as Krung Thep Maha Nakhon[b] and colloquially as Krung Thep,[c] is the capital and most populous city of Thailand. The city occupies 1,568.7 square kilometres (605.7 sq mi) in the Chao Phraya River delta in central Thailand and has an estimated population of 10.539 million as of 2020, 15.3 percent of the country's population. Over 14 million people (22.2 percent) lived within the surrounding Bangkok Metropolitan Region at the 2010 census, making Bangkok an extreme primate city, dwarfing Thailand's other urban centres in both size and importance to the national economy.