The size of Marrinup is approximately 43.2 square kilometres. It has 4 parks covering nearly 96.4% of total area. The population of Marrinup in 2006 was 558 people. By 2011 the population was 701 showing a population growth of 25.6% in the area during that time. The predominant age group in Marrinup is 50-59 years. Households in Marrinup are primarily childless couples and are likely to be repaying $1800 - $2399 per month on mortgage repayments. In general, people in Marrinup work in a machinery operators and drivers occupation. In 2006, 76.3% of the homes in Marrinup were owner-occupied compared with 69.7% in 2011.