The size of Appin is approximately 37.8 square kilometres. It has 2 parks covering nearly 8.2% of total area. The population of Appin in 2011 was 341 people. By 2016 the population was 3 showing a population decline of 99.1% in the area during that time. The predominant age group in Appin is 60-69 years. Households in Appin are primarily childless couples and are likely to be repaying $1000 - $1399 per month on mortgage repayments. In general, people in Appin work in a managers occupation. In 2006, 35.1% of the homes in Appin were owner-occupied compared with 75.5% in 2011.