The size of Mount Martha is approximately 30.3 square kilometres. It has 28 parks covering nearly 6.3% of total area. The population of Mount Martha in 2011 was 17,087 people. By 2016 the population was 18,552 showing a population growth of 8.6% in the area during that time. The predominant age group in Mount Martha is 40-49 years. Households in Mount Martha are primarily couples with children and are likely to be repaying $1800 - $2399 per month on mortgage repayments. In general, people in Mount Martha work in a professional occupation. In 2011, 83.3% of the homes in Mount Martha were owner-occupied compared with 82.4% in 2016. Currently the median sales price of houses in the area is $1,320,000.