The size of Cossack is approximately 226.7 square kilometres. It has 2 parks covering nearly 2.2% of total area. The population of Cossack in 2011 was 1,120 people. By 2016 the population was 1,215 showing a population growth of 8.5% in the area during that time. The predominant age group in Cossack is 50-59 years. Households in Cossack are primarily couples with children and are likely to be repaying $1800 - $2399 per month on mortgage repayments. In general, people in Cossack work in a professional occupation. In 2011, 63.6% of the homes in Cossack were owner-occupied compared with 73.2% in 2016. Currently the median sales price of houses in the area is $660,000.