Westfield, IA has a population of 159 and is the 25,437th largest city in the United States. The population density is 1,243 per sq mi which is 2176% higher than the Iowa average and 1272% higher than the national average. The median age in Westfield is 32 which is approximately 15% lower than the Iowa average of 38. In Westfield, 51% of the population over 15 years of age are married, 86% speak English and 13% speak Spanish. 79% of Westfield residents were born in Iowa, 17% were born out of state, 0% were born outside of the United States and 4% were foreign born.