The 2014 Dayton Metro Area, Ohio, population is 842,459. There are 494 people per square mile (population density). The median age is 39.1. The US median is 37.2. 50.24% of people in Dayton Metro Area, Ohio, are married. 12.78% are divorced. The average household size is 2.37 people. 28.24% of people are married, with children. 18.27% have children, but are single. Race in Dayton Metro Area, Ohio. 80.14% of people are white, 15.03% are black, 1.92% are asian, 0.14% are native american, and 0.60% claim 'Other'.