The ACT Government's latest population projections indicate 421,839 people will call Canberra home by the next decade, a jump of about 25,000 from July last year.

Much of that growth will be concentrated in Canberra's north and south-west.

But the ACT will remain a relatively young city, with more than twice as many 20 to 35-year-olds than those over the age of 65.