The size of Mount Johns is approximately 15.4 square kilometres. It has 1 park covering nearly 34.1% of total area. The population of Mount Johns in 2011 was 448 people. By 2016 the population was 546 showing a population growth of 21.9% in the area during that time. The predominant age group in Mount Johns is 30-39 years. Households in Mount Johns are primarily couples with children and are likely to be repaying $1800 - $2399 per month on mortgage repayments. In general, people in Mount Johns work in a professional occupation. In 2011, 18.3% of the homes in Mount Johns were owner-occupied compared with 19.4% in 2016. Currently the median sales price of houses in the area is $280,000.