| | Milpitas, CA | Alum Rock, CA | United States |
| Population | 79,593 | 12,218 | 329,725,481 |
| Female Population | 47.1% | 50.2% | 50.5% |
| Male Population | 53.0% | 49.8% | 49.5% |
| Median Age | 35.8 | 36.6 | 38.4 |
| space3 | | | |
| Population - 2010 | 66,694 | 16,049 | 309,327,143 |
| Population - 2000 | 62,698 | 13,479 | 285,036,114 |
| Population - 1990 | 50,686 | 11,337 | 251,960,433 |
| Pop. 2000 to Now | 21.0% | -10.4% | 15.6% |
| Pop. 1990 to Now | 49.7% | 6.5% | 30.8% |
| space4 | | | |
| Population Density | 5,829.7 | 14,476.3 | 93.4 |
| Land Area | 13.7 | 0.8 | 3,531,905.4 |
| Water Area | 0.0 | 0.0 | 264,836.8 |
| space | | | |
| Est. Total Population By Age | | | |
| | Milpitas, CA | Alum Rock, CA | United States |
| Age 0 to 4 | 6.6% | 5.8% | 5.9% |
| Age 5 to 9 | 6.1% | 6.5% | 6.1% |
| Age 10 to 14 | 5.8% | 7.1% | 6.6% |
| Age 15 to 17 | 3.4% | 3.5% | 3.9% |
| Age 18 to 20 | 2.6% | 4.4% | 4.0% |
| Age 21 to 24 | 3.9% | 7.0% | 5.2% |
| Age 25 to 34 | 19.8% | 14.0% | 13.8% |
| Age 35 to 44 | 15.5% | 13.0% | 12.9% |
| Age 45 to 54 | 12.2% | 15.3% | 12.6% |
| Age 55 to 59 | 6.1% | 5.9% | 6.7% |
| Age 60 to 64 | 6.0% | 4.7% | 6.3% |
| Age 65 to 74 | 7.2% | 7.3% | 9.6% |
| Age 75 to 84 | 3.3% | 3.7% | 4.5% |
| Age 85 and over | 1.6% | 1.8% | 1.9% |
| space1 | | | |
| Race | | | |
| | Milpitas, CA | Alum Rock, CA | United States |
| White | 10.6% | 9.3% | 59.4% |
| Black | 3.2% | 0.4% | 12.2% |
| Asian | 67.1% | 17.8% | 5.6% |
| Native American | 0.2% | 0.1% | 0.6% |
| Hawaiian, Pacific Islander | 0.2% | 0.0% | 0.2% |
| Other | 0.1% | 0.2% | 0.4% |
| Two or More Races | 4.7% | 0.7% | 3.2% |
| Hispanic | 13.9% | 71.4% | 18.4% |
| space2 | | | |
| Marriage & Family | | | |
| | Milpitas, CA | Alum Rock, CA | United States |
| Married Population | 57.7% | 47.5% | 49.8% |
| Currently Married | 56.0% | 45.4% | 48.0% |
| Married but Separated | 1.7% | 2.1% | 1.8% |
| Single Population | 42.3% | 52.5% | 50.2% |
| Never Married | 31.3% | 41.5% | 33.8% |
| Divorced | 6.4% | 5.9% | 10.8% |
| Widowed | 4.5% | 5.1% | 5.6% |
| space5 | | | |
| Household Size | 3.26 | 4.12 | 2.60 |
| Households | 23,681 | 2,892 | 124,010,992 |
| Family Households | 18,878 | 2,401 | 80,755,759 |
| Married couple, w/children | 40.5% | 33.9% | 30.5% |
| Married couple, no children | 39.4% | 30.6% | 42.9% |
| Non Family Households | 4,803 | 491 | 43,255,233 |
| Single householder, w/children | 8.7% | 20.0% | 15.8% |
| Single householder, no children | 11.5% | 15.5% | 10.8% |