Cedar Falls, IA has a population of 40,828 and is the 1,009th largest city in the United States. The population density is 1,412 per sq mi which is 2485% higher than the Iowa average and 1458% higher than the national average. The median age in Cedar Falls is 27 which is approximately 30% lower than the Iowa average of 38. In Cedar Falls, 45% of the population over 15 years of age are married, 93% speak English and 1% speak Spanish. 73% of Cedar Falls residents were born in Iowa, 21% were born out of state, 1% were born outside of the United States and 5% were foreign born.