The size of Grantham is approximately 49.3 square kilometres. It has 4 parks covering nearly 17% of total area. The population of Grantham in 2011 was 495 people. By 2016 the population was 616 showing a population growth of 24.4% in the area during that time. The predominant age group in Grantham is 50-59 years. Households in Grantham are primarily childless couples and are likely to be repaying $1000 - $1399 per month on mortgage repayments. In general, people in Grantham work in a labourer occupation. In 2011, 80.4% of the homes in Grantham were owner-occupied compared with 77% in 2016. Currently the median sales price of houses in the area is $363,350.