Ruiru's 2026 population is now estimated at 505,324. In 1950, the population of Ruiru was 676. Ruiru has grown by 20,622 in the last year, which represents a 4.25% 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 Ruiru, which typically includes Ruiru's population in addition to adjacent suburban areas.