DemographicsSouth Arm (Tas.) is approximately 10.98 square kilometres. In 2016 the population of South Arm (Tas.) was 880. The population is 49% male and 51% female. On average the monthly mortgage repayments in South Arm (Tas.) are $1000 to $1399. The most common weekly income bracket is $1000 to $1249 per week. Weekly rents in the area are on average $225 to $275.