| PEOPLE | Chicago | San Mateo | United States |
| Population | 2,695,598 | 97,207 | 308,035,306 |
| Pop. Density | 11,842 | 8,014 | 87 |
| Pop. Change | -7.16% | 5.16% | 8.07% |
| Median Age | 33.1 | 38.9 | 37.3 |
| Households | 1,045,560 | 38,233 | 116,716,292 |
| Household Size | 2.52 | 2.51 | 2.58 |
| Male Population | 48.53% | 48.83% | 49.27% |
| Female Population | 51.47% | 51.17% | 50.96% |
| Married Population | 31.20% | 46.97% | 47.02% |
| Single Population | 68.80% | 53.03% | 52.98% |
| ESTIMATED TOTAL POPULATION BY AGE | | | |
| Age 0 to 4 | 6.90% | 6.78% | 6.56% |
| Age 5 to 9 | 6.16% | 5.72% | 6.61% |
| Age 10 to 14 | 6.10% | 5.11% | 6.71% |
| Age 15 to 17 | 3.90% | 3.23% | 4.21% |
| Age 18 to 20 | 2.88% | 1.87% | 2.95% |
| Age 21 to 24 | 8.27% | 5.25% | 7.01% |
| Age 25 to 34 | 19.13% | 15.55% | 13.33% |
| Age 35 to 44 | 14.03% | 16.11% | 13.33% |
| Age 45 to 49 | 12.57% | 14.65% | 14.61% |
| Age 50 to 54 | 12.57% | 14.65% | 14.61% |
| Age 55 to 59 | 9.75% | 11.36% | 11.84% |
| Age 60 to 64 | 9.75% | 11.36% | 11.84% |
| Age 65 to 74 | 5.61% | 6.68% | 7.05% |
| Age 75 to 84 | 3.33% | 4.77% | 4.24% |
| Age 85 and over | 1.37% | 2.94% | 1.78% |
| RACE | | | |
| White | 44.99% | 57.83% | 72.41% |
| Black | 32.93% | 2.36% | 12.61% |
| Asian | 5.46% | 18.91% | 4.75% |
| American Indian | 0.49% | 0.52% | 0.95% |
| Other | 16.12% | 20.38% | 9.28% |
| Hispanic | 4.19% | 19.15% | 16.35% |
| Non-Hispanic | 95.81% | 80.85% | 83.65% |
| FAMILY | | | |
| Married, w/children | 26.11% | 34.91% | 30.42% |
| Married, no children | 31.85% | 41.72% | 42.46% |
| Single, w/children | 19.49% | 10.09% | 14.39% |
| Single, no children | 22.55% | 13.29% | 12.73% |
| Divorced | 9.22% | 10.79% | 10.62% |
| Separated | 7.36% | 5.63% | 4.97% |
| Widowed | 6.21% | 7.04% | 6.14% |
| Now Married | 31.70% | 46.32% | 46.32% |
| Never Married | 45.52% | 30.23% | 31.95% |
