| PEOPLE | Smithfield | Fairfield | United States |
| Population | 21,430 | 59,404 | 308,035,306 |
| Pop. Density | 815 | 1,987 | 87 |
| Pop. Change | 3.95% | 3.62% | 8.07% |
| Median Age | 41.9 | 40 | 37.3 |
| Households | 7,532 | 20,457 | 116,716,292 |
| Household Size | 2.4 | 2.69 | 2.58 |
| Male Population | 48.14% | 47.53% | 49.27% |
| Female Population | 51.86% | 52.47% | 50.96% |
| Married Population | 42.90% | 54.09% | 47.02% |
| Single Population | 57.10% | 45.91% | 52.98% |
| ESTIMATED TOTAL POPULATION BY AGE | | | |
| Age 0 to 4 | 3.48% | 5.90% | 6.56% |
| Age 5 to 9 | 4.40% | 7.56% | 6.61% |
| Age 10 to 14 | 5.42% | 7.74% | 6.71% |
| Age 15 to 17 | 3.62% | 4.22% | 4.21% |
| Age 18 to 20 | 6.80% | 4.51% | 2.95% |
| Age 21 to 24 | 12.01% | 6.59% | 7.01% |
| Age 25 to 34 | 6.97% | 7.27% | 13.33% |
| Age 35 to 44 | 11.58% | 13.88% | 13.33% |
| Age 45 to 49 | 15.71% | 15.99% | 14.61% |
| Age 50 to 54 | 15.71% | 15.99% | 14.61% |
| Age 55 to 59 | 12.66% | 11.33% | 11.84% |
| Age 60 to 64 | 12.66% | 11.33% | 11.84% |
| Age 65 to 74 | 7.48% | 6.75% | 7.05% |
| Age 75 to 84 | 5.68% | 5.10% | 4.24% |
| Age 85 and over | 4.18% | 3.16% | 1.78% |
| RACE | | | |
| White | 95.69% | 91.59% | 72.41% |
| Black | 1.20% | 1.83% | 12.61% |
| Asian | 1.31% | 3.71% | 4.75% |
| American Indian | 0.15% | 0.06% | 0.95% |
| Other | 1.65% | 2.81% | 9.28% |
| Hispanic | 1.39% | 0.00% | 16.35% |
| Non-Hispanic | 98.61% | 100.00% | 83.65% |
| FAMILY | | | |
| Married, w/children | 31.61% | 43.27% | 30.42% |
| Married, no children | 49.72% | 40.23% | 42.46% |
| Single, w/children | 7.72% | 7.60% | 14.39% |
| Single, no children | 10.95% | 8.90% | 12.73% |
| Divorced | 9.74% | 7.15% | 10.62% |
| Separated | 3.50% | 6.17% | 4.97% |
| Widowed | 7.92% | 7.01% | 6.14% |
| Now Married | 43.54% | 54.71% | 46.32% |
| Never Married | 35.31% | 24.96% | 31.95% |