Claim: Thailand's total area is approximately 513,000 square kilometers.

Thailand -LRB- -LSB- ˈtaɪlænd -RSB- or -LSB- ˈtaɪlənd -RSB- ; -LSB- : wikt : ประเทศไทย , ประเทศไทย -RSB- , , -LSB- pra.tʰêːt tʰaj -RSB- -RRB- , officially the Kingdom of Thailand -LRB- -LSB- : wikt : ราชอาณาจักรไทย , ราชอาณาจักรไทย -RSB- , -LSB- râːt.t͡ɕʰa.ʔaː.naː.t͡ɕàk tʰaj -RSB- -RRB- , formerly known as Siam -LRB- -LSB- : wikt : สยาม , สยาม -RSB- , -LSB- sa.jǎːm -RSB- -RRB- , is a country at the centre of the Indochinese peninsula in Southeast Asia . With a total area of approximately 513000 km2 , Thailand is the world 's 50th-largest country . It is the 20th-most-populous country in the world , with around 66 million people . The capital and largest city is Bangkok .   Thailand is a constitutional monarchy and has switched between parliamentary democracy and military junta for decades , the latest coup being in May 2014 by the National Council for Peace and Order . Its capital and most populous city is Bangkok . It is bordered to the north by Myanmar and Laos , to the east by Laos and Cambodia , to the south by the Gulf of Thailand and Malaysia , and to the west by the Andaman Sea and the southern extremity of Myanmar . Its maritime boundaries include Vietnam in the Gulf of Thailand to the southeast , and Indonesia and India on the Andaman Sea to the southwest .   The Thai economy is the world 's 20th largest by GDP at PPP and the 27th largest by nominal GDP . It became a newly industrialised country and a major exporter in the 1990s . Manufacturing , agriculture , and tourism are leading sectors of the economy . It is considered a middle power in the region and around the world .