Thailand divides its settlements (thesaban) into three categories by size: city municipalities (thesaban nakhon), towns (thesaban mueang) and townships (or subdistrict municipality) (thesaban tambon).[1] There are 33 city municipalities as of November 2024.
The national capital Bangkok and the special governed city Pattaya fall outside these divisions. They are "self-governing districts".
Due to the outdated nature of the thesaban system, any city municipality's growth subsequent to its settlement designation is not included in both area and population numbers. For this reason, the Department of Public Works and Town & Country Planning,[2] and each province's Provincial Administrative Organization regularly revise and publish up-to-date city boundaries (Thai: เขตเมือง) to reflect population growth. These revisions are royally decreed and published in the Royal Thai Government Gazette. The term เขตเมือง/khet mueang can also be translated to the term urban area, a widely used term to describe and designate large cities.
Most Thai cities' revised boundaries are contained in the province's capital district, known as Amphoe Mueang. Chiang Mai is the only city outside Bangkok to cover multiple districts in its urban area. Together, Bangkok and Chiang Mai are the only cities in Thailand with a population of over one million.
Thailand has an urbanization rate of 52% (2021), translating to 36,217,020 people of the total population.[3][4] This rate is based on the thesaban system, meaning that 8,442,107 people live in city municipalities, 4,437,112 people live in town municipalities and 23,337,801 people live in townships (subdistrict municipalities). According to the khet mueang system, 21,838,418 people (31.35% of total population) live in urban areas with a population greater than 150,000.
Several agencies issue population figures. Locally registered Thai populations are compiled by the Department of Local Administration (DLA). These figures are labeled as "Locally Registered Thai Population" and reflect the migrant, upcountry, and seasonal nature of Thai labor flows to the capital and tourist hot spots, yet maintain upcountry registration. Figures are very different from those by the National Statistics Office (NSO), which conducts the decennial census by attempting to count the total resident Thai population plus under 1,000 permanent resident foreigners. The result by the NSO is labeled as "Total Thai Population". Neither of the two offices release municipal level figures that include non-permanent residents, long-stay expatriates and figures for contracted foreign ASEAN migrants (a significant labor segment in cities like Bangkok, Pattaya, Chiang Mai, and Phuket, totaling two to three million workers), though this inclusion is being increasingly regularized since 2014. The NSO did release projected figures including regularized ASEAN migrants, i.e., "total resident population" down to the provincial level for 2017.[5]