Duarte, CA has a population of 21,792 and is the 2,003rd largest city in the United States. The population density is 3,257 per sq mi which is 1302% higher than the California average and 3495% higher than the national average. The median age in Duarte is 40 which is approximately 10% higher than the California average of 36. In Duarte, 54% of the population over 15 years of age are married, 47% speak English and 35% speak Spanish. 53% of Duarte residents were born in California, 12% were born out of state, 1% were born outside of the United States and 34% were foreign born.