| | Winnetka, IL | Leawood, KS | United States |
| Population | 12,658 | 33,748 | 329,725,481 |
| Female Population | 49.9% | 52.0% | 50.5% |
| Male Population | 50.2% | 48.0% | 49.5% |
| Median Age | 42.6 | 48.3 | 38.4 |
| space3 | | | |
| Population - 2010 | 12,212 | 31,938 | 309,327,143 |
| Population - 2000 | 12,419 | 27,656 | 285,036,114 |
| Population - 1990 | 12,174 | 19,693 | 251,960,433 |
| Pop. 2000 to Now | -1.8% | 25.4% | 15.6% |
| Pop. 1990 to Now | 0.2% | 76.1% | 30.8% |
| space4 | | | |
| Population Density | 3,324.9 | 2,234.5 | 93.4 |
| Land Area | 3.8 | 15.1 | 3,531,905.4 |
| Water Area | 0.1 | 0.1 | 264,836.8 |
| space | | | |
| Est. Total Population By Age | | | |
| | Winnetka, IL | Leawood, KS | United States |
| Age 0 to 4 | 8.7% | 5.4% | 5.9% |
| Age 5 to 9 | 9.5% | 6.4% | 6.1% |
| Age 10 to 14 | 8.2% | 7.2% | 6.6% |
| Age 15 to 17 | 5.7% | 3.6% | 3.9% |
| Age 18 to 20 | 2.0% | 2.1% | 4.0% |
| Age 21 to 24 | 2.3% | 2.8% | 5.2% |
| Age 25 to 34 | 5.1% | 7.2% | 13.8% |
| Age 35 to 44 | 10.9% | 11.6% | 12.9% |
| Age 45 to 54 | 17.3% | 13.7% | 12.6% |
| Age 55 to 59 | 6.7% | 10.3% | 6.7% |
| Age 60 to 64 | 6.7% | 8.7% | 6.3% |
| Age 65 to 74 | 11.4% | 13.3% | 9.6% |
| Age 75 to 84 | 4.2% | 5.5% | 4.5% |
| Age 85 and over | 1.3% | 2.1% | 1.9% |
| space1 | | | |
| Race | | | |
| | Winnetka, IL | Leawood, KS | United States |
| White | 91.0% | 87.6% | 59.4% |
| Black | 0.0% | 1.5% | 12.2% |
| Asian | 2.6% | 5.7% | 5.6% |
| Native American | 0.0% | 0.0% | 0.6% |
| Hawaiian, Pacific Islander | 0.1% | 0.0% | 0.2% |
| Other | 1.2% | 0.1% | 0.4% |
| Two or More Races | 3.8% | 2.0% | 3.2% |
| Hispanic | 1.3% | 3.0% | 18.4% |
| space2 | | | |
| Marriage & Family | | | |
| | Winnetka, IL | Leawood, KS | United States |
| Married Population | 74.0% | 71.0% | 49.8% |
| Currently Married | 73.7% | 70.8% | 48.0% |
| Married but Separated | 0.3% | 0.3% | 1.8% |
| Single Population | 26.0% | 29.0% | 50.2% |
| Never Married | 18.5% | 19.0% | 33.8% |
| Divorced | 5.1% | 6.6% | 10.8% |
| Widowed | 2.4% | 3.4% | 5.6% |
| space5 | | | |
| Household Size | 2.91 | 2.56 | 2.60 |
| Households | 4,353 | 13,143 | 124,010,992 |
| Family Households | 3,541 | 10,547 | 80,755,759 |
| Married couple, w/children | 48.7% | 35.0% | 30.5% |
| Married couple, no children | 46.6% | 58.3% | 42.9% |
| Non Family Households | 812 | 2,596 | 43,255,233 |
| Single householder, w/children | 2.6% | 3.3% | 15.8% |
| Single householder, no children | 2.1% | 3.3% | 10.8% |