| | Dyersburg, TN | Sumter, SC | United States |
| Population | 16,235 | 42,920 | 329,725,481 |
| Female Population | 53.6% | 51.2% | 50.5% |
| Male Population | 46.4% | 48.8% | 49.5% |
| Median Age | 41.9 | 32.3 | 38.4 |
| space3 | | | |
| Population - 2010 | 17,124 | 40,564 | 309,327,143 |
| Population - 2000 | 17,452 | 39,643 | 285,036,114 |
| Population - 1990 | 16,317 | 41,943 | 251,960,433 |
| Pop. 2000 to Now | -7.9% | -0.5% | 15.6% |
| Pop. 1990 to Now | -1.4% | -6.0% | 30.8% |
| space4 | | | |
| Population Density | 937.3 | 1,317.3 | 93.4 |
| Land Area | 17.3 | 32.6 | 3,531,905.4 |
| Water Area | 0.1 | 0.2 | 264,836.8 |
| space | | | |
| Est. Total Population By Age | | | |
| | Dyersburg, TN | Sumter, SC | United States |
| Age 0 to 4 | 5.6% | 8.0% | 5.9% |
| Age 5 to 9 | 7.5% | 7.4% | 6.1% |
| Age 10 to 14 | 6.4% | 7.6% | 6.6% |
| Age 15 to 17 | 4.0% | 4.0% | 3.9% |
| Age 18 to 20 | 4.9% | 4.4% | 4.0% |
| Age 21 to 24 | 4.3% | 6.6% | 5.2% |
| Age 25 to 34 | 10.2% | 14.8% | 13.8% |
| Age 35 to 44 | 11.6% | 10.2% | 12.9% |
| Age 45 to 54 | 14.6% | 10.1% | 12.6% |
| Age 55 to 59 | 6.2% | 5.7% | 6.7% |
| Age 60 to 64 | 5.5% | 5.3% | 6.3% |
| Age 65 to 74 | 12.3% | 8.6% | 9.6% |
| Age 75 to 84 | 5.0% | 4.0% | 4.5% |
| Age 85 and over | 1.9% | 3.1% | 1.9% |
| space1 | | | |
| Race | | | |
| | Dyersburg, TN | Sumter, SC | United States |
| White | 67.4% | 38.9% | 59.4% |
| Black | 23.6% | 48.0% | 12.2% |
| Asian | 0.6% | 2.1% | 5.6% |
| Native American | 0.1% | 0.2% | 0.6% |
| Hawaiian, Pacific Islander | 0.0% | 0.0% | 0.2% |
| Other | 0.0% | 0.6% | 0.4% |
| Two or More Races | 5.4% | 2.9% | 3.2% |
| Hispanic | 2.9% | 7.2% | 18.4% |
| space2 | | | |
| Marriage & Family | | | |
| | Dyersburg, TN | Sumter, SC | United States |
| Married Population | 44.6% | 47.5% | 49.8% |
| Currently Married | 41.0% | 43.4% | 48.0% |
| Married but Separated | 3.5% | 4.1% | 1.8% |
| Single Population | 55.4% | 52.5% | 50.2% |
| Never Married | 31.5% | 35.0% | 33.8% |
| Divorced | 14.0% | 10.0% | 10.8% |
| Widowed | 10.0% | 7.5% | 5.6% |
| space5 | | | |
| Household Size | 2.37 | 2.50 | 2.60 |
| Households | 6,631 | 16,595 | 124,010,992 |
| Family Households | 4,013 | 10,400 | 80,755,759 |
| Married couple, w/children | 23.6% | 24.6% | 30.5% |
| Married couple, no children | 39.4% | 38.4% | 42.9% |
| Non Family Households | 2,618 | 6,195 | 43,255,233 |
| Single householder, w/children | 22.9% | 23.7% | 15.8% |
| Single householder, no children | 14.0% | 13.3% | 10.8% |