Grand Terrace, CA has a population of 12,393 and is the 3,329th largest city in the United States. The population density is 3,539 per sq mi which is 1423% higher than the California average and 3806% higher than the national average. The median age in Grand Terrace is 38 which is approximately 5% higher than the California average of 36. In Grand Terrace, 53% of the population over 15 years of age are married, 71% speak English and 21% speak Spanish. 65% of Grand Terrace residents were born in California, 18% were born out of state, 1% were born outside of the United States and 15% were foreign born.