AreaVibes reveals the best places to live in District of Columbia for 2016 using our Livability Score. The Livability Score for each city in District of Columbia is calculated out of 100 from a unique algorithm based on various metrics, including: amenities, cost of living, crime, education, employment, housing and weather. District of Columbia has a population of 633,736 and a population density of 10.0 people per square mile. The capital city is Washington and the largest city in District of Columbia is Washington. To filter the results, use the dropdown options to sort by population or category.