Pittsburg, CA has a population of 67,998 and is the 542nd largest city in the United States. The population density is 3,980 per sq mi which is 1613% higher than the California average and 4293% higher than the national average. The median age in Pittsburg is 34 which is approximately 5% lower than the California average of 36. In Pittsburg, 51% of the population over 15 years of age are married, 50% speak English and 33% speak Spanish. 54% of Pittsburg residents were born in California, 12% were born out of state, 2% were born outside of the United States and 32% were foreign born.