DemographicsUnderbool is approximately 353.75 square kilometres. In 2016 the population of Underbool was 215. The population is 49% male and 51% female. On average the monthly mortgage repayments in Underbool are $1000 to $1399. The most common weekly income bracket is $300 to $399 per week. Weekly rents in the area are on average $0 to $74.