| | Wellesley, MA | Rancho Mirage, CA | United States |
| Population | 29,365 | 17,129 | 329,725,481 |
| Female Population | 56.7% | 48.7% | 50.5% |
| Male Population | 43.3% | 51.3% | 49.5% |
| Median Age | 35.3 | 65 | 38.4 |
| space3 | | | |
| Population - 2010 | 28,046 | 17,241 | 309,327,143 |
| Population - 2000 | 26,613 | 13,249 | 285,036,114 |
| Population - 1990 | 26,615 | 9,778 | 251,960,433 |
| Pop. 2000 to Now | 7.8% | 43.1% | 15.6% |
| Pop. 1990 to Now | 7.8% | 93.8% | 30.8% |
| space4 | | | |
| Population Density | 2,931.5 | 675.6 | 93.4 |
| Land Area | 10.0 | 25.4 | 3,531,905.4 |
| Water Area | 0.5 | 0.4 | 264,836.8 |
| space | | | |
| Est. Total Population By Age | | | |
| | Wellesley, MA | Rancho Mirage, CA | United States |
| Age 0 to 4 | 4.6% | 1.4% | 5.9% |
| Age 5 to 9 | 6.3% | 1.9% | 6.1% |
| Age 10 to 14 | 9.0% | 3.2% | 6.6% |
| Age 15 to 17 | 5.2% | 1.9% | 3.9% |
| Age 18 to 20 | 13.5% | 0.7% | 4.0% |
| Age 21 to 24 | 7.0% | 1.0% | 5.2% |
| Age 25 to 34 | 4.3% | 6.3% | 13.8% |
| Age 35 to 44 | 8.7% | 5.0% | 12.9% |
| Age 45 to 54 | 14.6% | 9.6% | 12.6% |
| Age 55 to 59 | 6.3% | 9.4% | 6.7% |
| Age 60 to 64 | 6.4% | 9.4% | 6.3% |
| Age 65 to 74 | 6.8% | 25.3% | 9.6% |
| Age 75 to 84 | 4.8% | 17.5% | 4.5% |
| Age 85 and over | 2.5% | 7.2% | 1.9% |
| space1 | | | |
| Race | | | |
| | Wellesley, MA | Rancho Mirage, CA | United States |
| White | 74.7% | 78.7% | 59.4% |
| Black | 2.5% | 1.6% | 12.2% |
| Asian | 13.2% | 4.6% | 5.6% |
| Native American | 0.0% | 0.8% | 0.6% |
| Hawaiian, Pacific Islander | 0.0% | 0.1% | 0.2% |
| Other | 0.4% | 0.0% | 0.4% |
| Two or More Races | 4.2% | 1.3% | 3.2% |
| Hispanic | 4.9% | 12.9% | 18.4% |
| space2 | | | |
| Marriage & Family | | | |
| | Wellesley, MA | Rancho Mirage, CA | United States |
| Married Population | 54.2% | 56.3% | 49.8% |
| Currently Married | 53.1% | 55.4% | 48.0% |
| Married but Separated | 1.1% | 0.9% | 1.8% |
| Single Population | 45.8% | 43.7% | 50.2% |
| Never Married | 37.6% | 19.6% | 33.8% |
| Divorced | 4.2% | 13.2% | 10.8% |
| Widowed | 4.0% | 10.9% | 5.6% |
| space5 | | | |
| Household Size | 2.82 | 1.93 | 2.60 |
| Households | 8,668 | 8,817 | 124,010,992 |
| Family Households | 6,800 | 4,768 | 80,755,759 |
| Married couple, w/children | 46.9% | 11.9% | 30.5% |
| Married couple, no children | 41.5% | 77.2% | 42.9% |
| Non Family Households | 1,868 | 4,049 | 43,255,233 |
| Single householder, w/children | 8.0% | 5.6% | 15.8% |
| Single householder, no children | 3.5% | 5.3% | 10.8% |