Gilbert, SC has a population of 824 and is the 16,393rd largest city in the United States. The population density is 304 per sq mi which is 106% higher than the South Carolina average and 236% higher than the national average. The median age in Gilbert is 41 which is approximately 6% higher than the South Carolina average of 39. In Gilbert, 68% of the population over 15 years of age are married, 86% speak English and 14% speak Spanish. 64% of Gilbert residents were born in South Carolina, 28% were born out of state, 0% were born outside of the United States and 8% were foreign born.