| PEOPLE | Simi Valley | San Buenaventura (Ventura) | United States |
| Population | 124,237 | 106,433 | 308,035,306 |
| Pop. Density | 2,995 | 4,915 | 87 |
| Pop. Change | 10.48% | 4.85% | 8.07% |
| Median Age | 37.7 | 38.9 | 37.3 |
| Households | 41,237 | 40,438 | 116,716,292 |
| Household Size | 2.99 | 2.58 | 2.58 |
| Male Population | 49.13% | 49.41% | 49.27% |
| Female Population | 50.87% | 50.59% | 50.96% |
| Married Population | 51.87% | 44.23% | 47.02% |
| Single Population | 48.13% | 55.77% | 52.98% |
| ESTIMATED TOTAL POPULATION BY AGE | | | |
| Age 0 to 4 | 6.07% | 5.79% | 6.56% |
| Age 5 to 9 | 6.74% | 5.97% | 6.61% |
| Age 10 to 14 | 7.42% | 6.51% | 6.71% |
| Age 15 to 17 | 4.74% | 4.20% | 4.21% |
| Age 18 to 20 | 2.86% | 2.73% | 2.95% |
| Age 21 to 24 | 6.07% | 6.27% | 7.01% |
| Age 25 to 34 | 12.36% | 13.39% | 13.33% |
| Age 35 to 44 | 14.92% | 13.69% | 13.33% |
| Age 45 to 49 | 16.53% | 15.76% | 14.61% |
| Age 50 to 54 | 16.53% | 15.76% | 14.61% |
| Age 55 to 59 | 11.68% | 12.39% | 11.84% |
| Age 60 to 64 | 11.68% | 12.39% | 11.84% |
| Age 65 to 74 | 6.13% | 6.48% | 7.05% |
| Age 75 to 84 | 3.18% | 4.51% | 4.24% |
| Age 85 and over | 1.30% | 2.31% | 1.78% |
| RACE | | | |
| White | 75.34% | 76.62% | 72.41% |
| Black | 1.40% | 1.62% | 12.61% |
| Asian | 9.30% | 3.44% | 4.75% |
| American Indian | 0.61% | 1.21% | 0.95% |
| Other | 13.35% | 17.11% | 9.28% |
| Hispanic | 34.23% | 5.01% | 16.35% |
| Non-Hispanic | 65.77% | 94.99% | 83.65% |
| FAMILY | | | |
| Married, w/children | 37.59% | 30.98% | 30.42% |
| Married, no children | 40.72% | 41.75% | 42.46% |
| Single, w/children | 10.02% | 13.75% | 14.39% |
| Single, no children | 11.67% | 13.52% | 12.73% |
| Divorced | 11.12% | 13.94% | 10.62% |
| Separated | 3.54% | 4.91% | 4.97% |
| Widowed | 4.17% | 6.26% | 6.14% |
| Now Married | 51.95% | 44.04% | 46.32% |
| Never Married | 29.23% | 30.85% | 31.95% |