| | La Mesa, CA | Rancho Mirage, CA | United States |
| Population | 61,040 | 17,129 | 329,725,481 |
| Female Population | 53.3% | 48.7% | 50.5% |
| Male Population | 46.7% | 51.3% | 49.5% |
| Median Age | 36 | 65 | 38.4 |
| space3 | | | |
| Population - 2010 | 57,347 | 17,241 | 309,327,143 |
| Population - 2000 | 54,749 | 13,249 | 285,036,114 |
| Population - 1990 | 52,931 | 9,778 | 251,960,433 |
| Pop. 2000 to Now | 9.1% | 43.1% | 15.6% |
| Pop. 1990 to Now | 12.8% | 93.8% | 30.8% |
| space4 | | | |
| Population Density | 6,712.1 | 675.6 | 93.4 |
| Land Area | 9.1 | 25.4 | 3,531,905.4 |
| Water Area | 0.0 | 0.4 | 264,836.8 |
| space | | | |
| Est. Total Population By Age | | | |
| | La Mesa, CA | Rancho Mirage, CA | United States |
| Age 0 to 4 | 7.4% | 1.4% | 5.9% |
| Age 5 to 9 | 5.0% | 1.9% | 6.1% |
| Age 10 to 14 | 5.4% | 3.2% | 6.6% |
| Age 15 to 17 | 2.6% | 1.9% | 3.9% |
| Age 18 to 20 | 2.8% | 0.7% | 4.0% |
| Age 21 to 24 | 6.3% | 1.0% | 5.2% |
| Age 25 to 34 | 18.6% | 6.3% | 13.8% |
| Age 35 to 44 | 14.3% | 5.0% | 12.9% |
| Age 45 to 54 | 11.6% | 9.6% | 12.6% |
| Age 55 to 59 | 5.0% | 9.4% | 6.7% |
| Age 60 to 64 | 6.3% | 9.4% | 6.3% |
| Age 65 to 74 | 8.3% | 25.3% | 9.6% |
| Age 75 to 84 | 3.8% | 17.5% | 4.5% |
| Age 85 and over | 2.4% | 7.2% | 1.9% |
| space1 | | | |
| Race | | | |
| | La Mesa, CA | Rancho Mirage, CA | United States |
| White | 54.4% | 78.7% | 59.4% |
| Black | 7.3% | 1.6% | 12.2% |
| Asian | 6.6% | 4.6% | 5.6% |
| Native American | 0.1% | 0.8% | 0.6% |
| Hawaiian, Pacific Islander | 0.3% | 0.1% | 0.2% |
| Other | 0.2% | 0.0% | 0.4% |
| Two or More Races | 5.3% | 1.3% | 3.2% |
| Hispanic | 25.8% | 12.9% | 18.4% |
| space2 | | | |
| Marriage & Family | | | |
| | La Mesa, CA | Rancho Mirage, CA | United States |
| Married Population | 43.9% | 56.3% | 49.8% |
| Currently Married | 42.3% | 55.4% | 48.0% |
| Married but Separated | 1.7% | 0.9% | 1.8% |
| Single Population | 56.1% | 43.7% | 50.2% |
| Never Married | 37.7% | 19.6% | 33.8% |
| Divorced | 13.4% | 13.2% | 10.8% |
| Widowed | 5.1% | 10.9% | 5.6% |
| space5 | | | |
| Household Size | 2.46 | 1.93 | 2.60 |
| Households | 24,475 | 8,817 | 124,010,992 |
| Family Households | 14,005 | 4,768 | 80,755,759 |
| Married couple, w/children | 30.7% | 11.9% | 30.5% |
| Married couple, no children | 39.0% | 77.2% | 42.9% |
| Non Family Households | 10,470 | 4,049 | 43,255,233 |
| Single householder, w/children | 16.5% | 5.6% | 15.8% |
| Single householder, no children | 13.8% | 5.3% | 10.8% |