Eau Claire, MI has a population of 612 and is the 18,328th largest city in the United States. The population density is 735 per sq mi which is 629% higher than the Michigan average and 712% higher than the national average. The median age in Eau Claire is 33 which is approximately 16% lower than the Michigan average of 40. In Eau Claire, 49% of the population over 15 years of age are married, 82% speak English and 18% speak Spanish. 64% of Eau Claire residents were born in Michigan, 22% were born out of state, 3% were born outside of the United States and 11% were foreign born.