Sac City, IA has a population of 2,185 and is the 10,513th largest city in the United States. The population density is 450 per sq mi which is 723% higher than the Iowa average and 396% higher than the national average. The median age in Sac City is 50 which is approximately 31% higher than the Iowa average of 38. In Sac City, 60% of the population over 15 years of age are married, 98% speak English and 1% speak Spanish. 81% of Sac City residents were born in Iowa, 18% were born out of state, 0% were born outside of the United States and 1% were foreign born.