| PEOPLE | Katy | Irmo | United States |
| Population | 14,102 | 11,097 | 308,035,306 |
| Pop. Density | 1,253 | 1,772 | 87 |
| Pop. Change | 43.26% | 6.55% | 8.07% |
| Median Age | 36.3 | 36.5 | 37.3 |
| Households | 4,752 | 4,326 | 116,716,292 |
| Household Size | 3.05 | 2.62 | 2.58 |
| Male Population | 49.16% | 47.27% | 49.27% |
| Female Population | 50.84% | 52.73% | 50.96% |
| Married Population | 55.86% | 58.44% | 47.02% |
| Single Population | 44.14% | 41.56% | 52.98% |
| ESTIMATED TOTAL POPULATION BY AGE | | | |
| Age 0 to 4 | 7.01% | 6.99% | 6.56% |
| Age 5 to 9 | 6.88% | 6.44% | 6.61% |
| Age 10 to 14 | 8.09% | 7.05% | 6.71% |
| Age 15 to 17 | 5.76% | 4.67% | 4.21% |
| Age 18 to 20 | 2.99% | 2.87% | 2.95% |
| Age 21 to 24 | 5.80% | 5.84% | 7.01% |
| Age 25 to 34 | 11.86% | 14.01% | 13.33% |
| Age 35 to 44 | 13.54% | 13.63% | 13.33% |
| Age 45 to 49 | 15.98% | 15.66% | 14.61% |
| Age 50 to 54 | 15.98% | 15.66% | 14.61% |
| Age 55 to 59 | 10.87% | 12.63% | 11.84% |
| Age 60 to 64 | 10.87% | 12.63% | 11.84% |
| Age 65 to 74 | 5.99% | 6.53% | 7.05% |
| Age 75 to 84 | 3.47% | 2.73% | 4.24% |
| Age 85 and over | 1.74% | 0.94% | 1.78% |
| RACE | | | |
| White | 80.09% | 64.62% | 72.41% |
| Black | 5.26% | 29.88% | 12.61% |
| Asian | 1.55% | 1.60% | 4.75% |
| American Indian | 0.61% | 0.37% | 0.95% |
| Other | 12.49% | 3.52% | 9.28% |
| Hispanic | 1.48% | 0.28% | 16.35% |
| Non-Hispanic | 98.52% | 99.72% | 83.65% |
| FAMILY | | | |
| Married, w/children | 36.13% | 29.78% | 30.42% |
| Married, no children | 41.05% | 42.58% | 42.46% |
| Single, w/children | 12.53% | 16.10% | 14.39% |
| Single, no children | 10.30% | 11.54% | 12.73% |
| Divorced | 9.22% | 8.65% | 10.62% |
| Separated | 5.20% | 3.13% | 4.97% |
| Widowed | 3.83% | 2.35% | 6.14% |
| Now Married | 55.90% | 58.67% | 46.32% |
| Never Married | 25.84% | 27.20% | 31.95% |
