| PEOPLE | Westminster | Atascadero | United States |
| Population | 106,114 | 28,310 | 308,035,306 |
| Pop. Density | 3,363 | 1,104 | 87 |
| Pop. Change | 5.14% | 7.26% | 8.07% |
| Median Age | 35.1 | 41 | 37.3 |
| Households | 42,041 | 10,737 | 116,716,292 |
| Household Size | 2.55 | 2.52 | 2.58 |
| Male Population | 49.56% | 50.79% | 49.27% |
| Female Population | 50.44% | 49.21% | 50.96% |
| Married Population | 52.21% | 48.00% | 47.02% |
| Single Population | 47.79% | 52.00% | 52.98% |
| ESTIMATED TOTAL POPULATION BY AGE | | | |
| Age 0 to 4 | 7.04% | 5.89% | 6.56% |
| Age 5 to 9 | 6.57% | 5.76% | 6.61% |
| Age 10 to 14 | 6.40% | 5.90% | 6.71% |
| Age 15 to 17 | 4.06% | 3.88% | 4.21% |
| Age 18 to 20 | 2.48% | 2.20% | 2.95% |
| Age 21 to 24 | 7.07% | 5.85% | 7.01% |
| Age 25 to 34 | 16.18% | 13.44% | 13.33% |
| Age 35 to 44 | 14.24% | 12.15% | 13.33% |
| Age 45 to 49 | 15.35% | 16.54% | 14.61% |
| Age 50 to 54 | 15.35% | 16.54% | 14.61% |
| Age 55 to 59 | 11.50% | 15.37% | 11.84% |
| Age 60 to 64 | 11.50% | 15.37% | 11.84% |
| Age 65 to 74 | 5.22% | 7.15% | 7.05% |
| Age 75 to 84 | 2.81% | 4.00% | 4.24% |
| Age 85 and over | 1.09% | 1.87% | 1.78% |
| RACE | | | |
| White | 82.03% | 86.39% | 72.41% |
| Black | 1.42% | 2.07% | 12.61% |
| Asian | 5.41% | 2.42% | 4.75% |
| American Indian | 0.95% | 1.04% | 0.95% |
| Other | 10.19% | 8.08% | 9.28% |
| Hispanic | 1.57% | 97.13% | 16.35% |
| Non-Hispanic | 98.43% | 2.87% | 83.65% |
| FAMILY | | | |
| Married, w/children | 32.75% | 28.78% | 30.42% |
| Married, no children | 42.39% | 47.95% | 42.46% |
| Single, w/children | 13.73% | 12.97% | 14.39% |
| Single, no children | 11.13% | 10.31% | 12.73% |
| Divorced | 12.27% | 12.93% | 10.62% |
| Separated | 3.32% | 4.64% | 4.97% |
| Widowed | 3.61% | 4.92% | 6.14% |
| Now Married | 51.45% | 48.71% | 46.32% |
| Never Married | 29.35% | 28.81% | 31.95% |
