The size of St Clair is approximately 0.9 square kilometres. It has 12 parks covering nearly 31.5% of total area. The population of St Clair in 2011 was 2,206 people. By 2016 the population was 1,701 showing a population decline of 22.9% in the area during that time. The predominant age group in St Clair is 20-29 years. Households in St Clair are primarily childless couples and are likely to be repaying $1800 - $2399 per month on mortgage repayments. In general, people in St Clair work in a professional occupation. In 2011, 62% of the homes in St Clair were owner-occupied compared with 52% in 2016. Currently the median sales price of houses in the area is $625,000.