There are 196 Post Offices in San Diego County, California, serving a population of 3,283,665 people in an area of 4,206 square miles. There is 1 Post Office per 16,753 people, and 1 Post Office per 21 square miles.
In California, San Diego County is ranked 44th of 58 counties in Post Offices per capita, and 10th of 58 counties in Post Offices per square mile.