The size of Bletchley is approximately 23.6 square kilometres. The population of Bletchley in 2011 was 415 people. By 2016 the population was 72 showing a population decline of 82.7% in the area during that time. The predominant age group in Bletchley is 40-49 years. Households in Bletchley are primarily couples with children and are likely to be repaying $1800 - $2399 per month on mortgage repayments. In general, people in Bletchley work in a managers occupation. In 2011, 95.3% of the homes in Bletchley were owner-occupied compared with 62.9% in 2016.