The size of Llanarth is approximately 4,941.5 square kilometres. It has 4 parks covering nearly 0.4% of total area. The population of Llanarth in 2011 was 456 people. By 2016 the population was 39 showing a population decline of 91.4% in the area during that time. The predominant age group in Llanarth is 0-9 years. Households in Llanarth are primarily childless couples and are likely to be repaying under $300 per month on mortgage repayments. In general, people in Llanarth work in a managers occupation. In 2006, 70.9% of the homes in Llanarth were owner-occupied compared with 75% in 2011.