DemographicsKnowsley is approximately 86.15 square kilometres. In 2016 the population of Knowsley was 160. The population is 59% male and 41% female. On average the monthly mortgage repayments in Knowsley are $800 to $999. The most common weekly income bracket is $300 to $399 per week. Weekly rents in the area are on average $0 to $74.