Karaj's 2021 population is now estimated at 1,582,351. In 1950, the population of Karaj was 7,159. Karaj has grown by 1,938 since 2015, which represents a 0.12% 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 Karaj, which typically includes Karaj's population in addition to adjacent suburban areas.