Ainsworth, IA has a population of 451 and is the 20,186th largest city in the United States. The population density is 1,207 per sq mi which is 2017% higher than the Iowa average and 1232% higher than the national average. The median age in Ainsworth is 32 which is approximately 16% lower than the Iowa average of 38. In Ainsworth, 63% of the population over 15 years of age are married, 67% speak English and 31% speak Spanish. 62% of Ainsworth residents were born in Iowa, 15% were born out of state, 0% were born outside of the United States and 23% were foreign born.