The size of Thirlmere is approximately 33.3 square kilometres. It has 16 parks covering nearly 26.8% of total area. The population of Thirlmere in 2011 was 3,529 people. By 2016 the population was 4,031 showing a population growth of 14.2% in the area during that time. The predominant age group in Thirlmere is 0-9 years. Households in Thirlmere are primarily couples with children and are likely to be repaying $1800 - $2399 per month on mortgage repayments. In general, people in Thirlmere work in a trades occupation. In 2011, 75.6% of the homes in Thirlmere were owner-occupied compared with 74.3% in 2016. Currently the median sales price of houses in the area is $720,000.