DemographicsGrosmont is approximately 839.39 square kilometres. In 2016 the population of Grosmont was 141. The population is 51% male and 49% female. On average the monthly mortgage repayments in Grosmont are $0 to $299. The most common weekly income bracket is $400 to $499 per week. Weekly rents in the area are on average $0 to $74.