Over the years Cranbourne has changed from a small country town to a rapidly growing suburb. The exact time of when Cranbourne had changed from town to suburb is not really known. The number of people living in Cranbourne has grown quickly since the 1970s. There were 1,800 people in 1976, rising to 14,005 in 1986 and 18,886 in 1991. Cranbourne's current population is estimated to be at least 30,000 people.