Duncan is a city located in South Carolina. With a 2020 population of 3,663, it is the 81st largest city in South Carolina and the 5650th largest city in the United States. Duncan is currently growing at a rate of 1.92% annually and its population has increased by 15.15% since the most recent census, which recorded a population of 3,181 in 2010. Spanning over 5 miles, Duncan has a population density of 682 people per square mile.
The average household income in Duncan is $46,650 with a poverty rate of 19.82%. The median rental costs in recent years comes to $814 per month, and the median house value is $96,200. The median age in Duncan is 30.1 years, 25.6 years for males, and 33.4 years for females. For every 100 females there are 82.9 males.