Runnells, IA has a population of 514 and is the 19,365th largest city in the United States. The population density is 1,207 per sq mi which is 2109% higher than the Iowa average and 1232% higher than the national average. The median age in Runnells is 36 which is approximately 5% lower than the Iowa average of 38. In Runnells, 56% of the population over 15 years of age are married, 100% speak English and 0% speak Spanish. 94% of Runnells residents were born in Iowa, 6% were born out of state, 0% were born outside of the United States and 0% were foreign born.