Westfalen's 2025 population is now estimated at 341,871. In 1950, the population of Westfalen was 209,906. Westfalen has grown by 1,445 in the last year, which represents a 0.42% 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 Westfalen, which typically includes Westfalen's population in addition to adjacent suburban areas.