Rancho San Diego, CA has a population of 22,018 and is the 1,975th largest city in the United States. The population density is 2,532 per sq mi which is 990% higher than the California average and 2695% higher than the national average. The median age in Rancho San Diego is 43 which is approximately 18% higher than the California average of 36. In Rancho San Diego, 60% of the population over 15 years of age are married, 69% speak English and 11% speak Spanish. 50% of Rancho San Diego residents were born in California, 27% were born out of state, 1% were born outside of the United States and 23% were foreign born.