The size of Buchanan is approximately 52.1 square kilometres. The population of Buchanan in 2011 was 449 people. By 2016 the population was 31 showing a population decline of 93.1% in the area during that time. The predominant age group in Buchanan is 0-9 years. Households in Buchanan are primarily couples with children and are likely to be repaying $800 - $999 per month on mortgage repayments. In general, people in Buchanan work in a managers occupation. In 2011, 83.8% of the homes in Buchanan were owner-occupied compared with 83.4% in 2016.