DemographicsKelvinhaugh is approximately 42.41 square kilometres. In 2016 the population of Kelvinhaugh was 44. The population is 58% male and 42% female. On average the monthly mortgage repayments in Kelvinhaugh are $0 to $299. The most common weekly income bracket is $300 to $399 per week. Weekly rents in the area are on average $150 to $199.