DemographicsMount Hallen is approximately 52.54 square kilometres. In 2016 the population of Mount Hallen was 458. The population is 49% male and 51% female. On average the monthly mortgage repayments in Mount Hallen are $1000 to $1399. The most common weekly income bracket is $300 to $399 per week. Weekly rents in the area are on average $275 to $349.