The size of Thornlands is approximately 21.7 square kilometres. It has 39 parks covering nearly 6.2% of total area. The population of Thornlands in 2011 was 12,806 people. By 2016 the population was 14,696 showing a population growth of 14.8% in the area during that time. The predominant age group in Thornlands is 10-19 years. Households in Thornlands are primarily couples with children and are likely to be repaying $1800 - $2399 per month on mortgage repayments. In general, people in Thornlands work in a professional occupation. In 2011, 76.6% of the homes in Thornlands were owner-occupied compared with 73.6% in 2016. Currently the median sales price of houses in the area is $680,000.