The size of Theodore is approximately 3.1 square kilometres. It has 9 parks covering nearly 40.9% of total area. The population of Theodore in 2011 was 4,020 people. By 2016 the population was 3,797 showing a population decline of 5.5% in the area during that time. The predominant age group in Theodore is 50-59 years. Households in Theodore are primarily couples with children and are likely to be repaying $1800 - $2399 per month on mortgage repayments. In general, people in Theodore work in a clerical occupation. In 2011, 79.1% of the homes in Theodore were owner-occupied compared with 79% in 2016. Currently the median sales price of houses in the area is $740,000.