The size of Gumlu is approximately 388.1 square kilometres. It has 2 parks covering nearly 2.6% of total area. The population of Gumlu in 2011 was 221 people. By 2016 the population was 165 showing a population decline of 25.3% in the area during that time. The predominant age group in Gumlu is 30-39 years. Households in Gumlu are primarily childless couples and are likely to be repaying under $300 per month on mortgage repayments. In general, people in Gumlu work in a managers occupation. In 2011, 62.2% of the homes in Gumlu were owner-occupied compared with 70% in 2016.