| | Piedmont, CA | Campbell, CA | United States |
| Population | 11,368 | 43,954 | 329,725,481 |
| Female Population | 49.5% | 49.9% | 50.5% |
| Male Population | 50.5% | 50.1% | 49.5% |
| Median Age | 45.4 | 39.1 | 38.4 |
| space3 | | | |
| Population - 2010 | 10,709 | 40,672 | 309,327,143 |
| Population - 2000 | 10,952 | 38,138 | 285,036,114 |
| Population - 1990 | 10,602 | 37,256 | 251,960,433 |
| Pop. 2000 to Now | 3.5% | 11.3% | 15.6% |
| Pop. 1990 to Now | 6.9% | 13.9% | 30.8% |
| space4 | | | |
| Population Density | 6,687.1 | 7,226.9 | 93.4 |
| Land Area | 1.7 | 6.1 | 3,531,905.4 |
| Water Area | 0.0 | 0.0 | 264,836.8 |
| space | | | |
| Est. Total Population By Age | | | |
| | Piedmont, CA | Campbell, CA | United States |
| Age 0 to 4 | 5.2% | 6.8% | 5.9% |
| Age 5 to 9 | 6.9% | 6.5% | 6.1% |
| Age 10 to 14 | 9.6% | 5.4% | 6.6% |
| Age 15 to 17 | 5.5% | 3.2% | 3.9% |
| Age 18 to 20 | 3.2% | 1.9% | 4.0% |
| Age 21 to 24 | 1.7% | 2.8% | 5.2% |
| Age 25 to 34 | 5.0% | 15.1% | 13.8% |
| Age 35 to 44 | 12.3% | 16.4% | 12.9% |
| Age 45 to 54 | 19.4% | 13.4% | 12.6% |
| Age 55 to 59 | 6.0% | 8.1% | 6.7% |
| Age 60 to 64 | 4.7% | 6.2% | 6.3% |
| Age 65 to 74 | 13.4% | 8.0% | 9.6% |
| Age 75 to 84 | 3.7% | 3.4% | 4.5% |
| Age 85 and over | 3.3% | 2.7% | 1.9% |
| space1 | | | |
| Race | | | |
| | Piedmont, CA | Campbell, CA | United States |
| White | 70.7% | 48.3% | 59.4% |
| Black | 1.4% | 2.2% | 12.2% |
| Asian | 20.6% | 24.9% | 5.6% |
| Native American | 0.0% | 0.2% | 0.6% |
| Hawaiian, Pacific Islander | 0.1% | 0.0% | 0.2% |
| Other | 0.1% | 0.6% | 0.4% |
| Two or More Races | 3.9% | 5.3% | 3.2% |
| Hispanic | 3.2% | 18.4% | 18.4% |
| space2 | | | |
| Marriage & Family | | | |
| | Piedmont, CA | Campbell, CA | United States |
| Married Population | 64.3% | 55.3% | 49.8% |
| Currently Married | 63.9% | 54.2% | 48.0% |
| Married but Separated | 0.4% | 1.1% | 1.8% |
| Single Population | 35.7% | 44.7% | 50.2% |
| Never Married | 22.1% | 31.0% | 33.8% |
| Divorced | 8.2% | 9.1% | 10.8% |
| Widowed | 5.4% | 4.6% | 5.6% |
| space5 | | | |
| Household Size | 2.97 | 2.52 | 2.60 |
| Households | 3,821 | 17,346 | 124,010,992 |
| Family Households | 3,075 | 11,128 | 80,755,759 |
| Married couple, w/children | 47.4% | 35.6% | 30.5% |
| Married couple, no children | 39.9% | 42.2% | 42.9% |
| Non Family Households | 746 | 6,218 | 43,255,233 |
| Single householder, w/children | 7.5% | 13.1% | 15.8% |
| Single householder, no children | 5.1% | 9.1% | 10.8% |