Surat Thani's 2025 population is now estimated at 528,783. In 1950, the population of Surat Thani was 15,628. Surat Thani has grown by 6,552 in the last year, which represents a 1.25% annual change.These population estimates and projections come from the latest revision of the UN World Urbanization Prospects. These estimates represent the Urban agglomeration of Surat Thani, which typically includes Surat Thani's population in addition to adjacent suburban areas.