| | Piedmont, SD | Sioux Falls, SD | United States |
| Population | 1,017 | 189,258 | 329,725,481 |
| Female Population | 47.6% | 49.8% | 50.5% |
| Male Population | 52.4% | 50.2% | 49.5% |
| Median Age | 40.6 | 34.5 | 38.4 |
| space3 | | | |
| Population - 2010 | 886 | 154,538 | 309,327,143 |
| Population - 2000 | 178 | 123,975 | 285,036,114 |
| Population - 1990 | 142 | 100,814 | 251,960,433 |
| Pop. 2000 to Now | 402.8% | 51.5% | 15.6% |
| Pop. 1990 to Now | 530.3% | 86.3% | 30.8% |
| space4 | | | |
| Population Density | 772.8 | 2,441.7 | 93.4 |
| Land Area | 1.3 | 77.5 | 3,531,905.4 |
| Water Area | 0.0 | 0.5 | 264,836.8 |
| space | | | |
| Est. Total Population By Age | | | |
| | Piedmont, SD | Sioux Falls, SD | United States |
| Age 0 to 4 | 3.7% | 7.4% | 5.9% |
| Age 5 to 9 | 7.9% | 7.2% | 6.1% |
| Age 10 to 14 | 9.5% | 6.6% | 6.6% |
| Age 15 to 17 | 7.3% | 3.9% | 3.9% |
| Age 18 to 20 | 1.5% | 3.6% | 4.0% |
| Age 21 to 24 | 3.4% | 5.9% | 5.2% |
| Age 25 to 34 | 13.3% | 16.1% | 13.8% |
| Age 35 to 44 | 6.0% | 13.7% | 12.9% |
| Age 45 to 54 | 10.7% | 11.2% | 12.6% |
| Age 55 to 59 | 6.4% | 6.0% | 6.7% |
| Age 60 to 64 | 9.3% | 5.4% | 6.3% |
| Age 65 to 74 | 18.2% | 8.3% | 9.6% |
| Age 75 to 84 | 1.2% | 3.2% | 4.5% |
| Age 85 and over | 1.6% | 1.5% | 1.9% |
| space1 | | | |
| Race | | | |
| | Piedmont, SD | Sioux Falls, SD | United States |
| White | 91.0% | 79.9% | 59.4% |
| Black | 3.6% | 6.6% | 12.2% |
| Asian | 0.7% | 2.4% | 5.6% |
| Native American | 0.3% | 1.7% | 0.6% |
| Hawaiian, Pacific Islander | 0.0% | 0.0% | 0.2% |
| Other | 0.0% | 0.0% | 0.4% |
| Two or More Races | 3.0% | 3.7% | 3.2% |
| Hispanic | 1.4% | 5.5% | 18.4% |
| space2 | | | |
| Marriage & Family | | | |
| | Piedmont, SD | Sioux Falls, SD | United States |
| Married Population | 62.2% | 49.8% | 49.8% |
| Currently Married | 62.1% | 48.6% | 48.0% |
| Married but Separated | 0.1% | 1.2% | 1.8% |
| Single Population | 37.8% | 50.2% | 50.2% |
| Never Married | 29.3% | 34.5% | 33.8% |
| Divorced | 5.9% | 11.4% | 10.8% |
| Widowed | 2.6% | 4.3% | 5.6% |
| space5 | | | |
| Household Size | 2.40 | 2.37 | 2.60 |
| Households | 424 | 77,326 | 124,010,992 |
| Family Households | 284 | 46,150 | 80,755,759 |
| Married couple, w/children | 33.1% | 34.6% | 30.5% |
| Married couple, no children | 55.6% | 40.2% | 42.9% |
| Non Family Households | 140 | 31,176 | 43,255,233 |
| Single householder, w/children | 8.5% | 18.3% | 15.8% |
| Single householder, no children | 2.8% | 6.8% | 10.8% |