| | Lyndon, KS | Emporia, KS | United States |
| Population | 1,117 | 24,220 | 329,725,481 |
| Female Population | 52.0% | 52.2% | 50.5% |
| Male Population | 48.0% | 47.8% | 49.5% |
| Median Age | 36 | 29 | 38.4 |
| space3 | | | |
| Population - 2010 | 1,054 | 24,910 | 309,327,143 |
| Population - 2000 | 1,038 | 26,760 | 285,036,114 |
| Population - 1990 | 964 | 25,512 | 251,960,433 |
| Pop. 2000 to Now | -2.4% | -8.4% | 15.6% |
| Pop. 1990 to Now | 5.1% | -4.0% | 30.8% |
| space4 | | | |
| Population Density | 1,250.8 | 2,021.5 | 93.4 |
| Land Area | 0.9 | 12.0 | 3,531,905.4 |
| Water Area | 0.0 | 0.1 | 264,836.8 |
| space | | | |
| Est. Total Population By Age | | | |
| | Lyndon, KS | Emporia, KS | United States |
| Age 0 to 4 | 8.4% | 6.3% | 5.9% |
| Age 5 to 9 | 10.9% | 6.8% | 6.1% |
| Age 10 to 14 | 4.5% | 5.7% | 6.6% |
| Age 15 to 17 | 6.1% | 3.2% | 3.9% |
| Age 18 to 20 | 4.7% | 10.0% | 4.0% |
| Age 21 to 24 | 3.7% | 12.0% | 5.2% |
| Age 25 to 34 | 10.0% | 12.6% | 13.8% |
| Age 35 to 44 | 9.6% | 10.7% | 12.9% |
| Age 45 to 54 | 15.3% | 9.6% | 12.6% |
| Age 55 to 59 | 7.4% | 3.8% | 6.7% |
| Age 60 to 64 | 4.3% | 5.9% | 6.3% |
| Age 65 to 74 | 9.4% | 7.5% | 9.6% |
| Age 75 to 84 | 4.7% | 4.0% | 4.5% |
| Age 85 and over | 1.1% | 2.0% | 1.9% |
| space1 | | | |
| Race | | | |
| | Lyndon, KS | Emporia, KS | United States |
| White | 94.5% | 63.0% | 59.4% |
| Black | 2.2% | 2.4% | 12.2% |
| Asian | 0.0% | 2.0% | 5.6% |
| Native American | 0.0% | 0.3% | 0.6% |
| Hawaiian, Pacific Islander | 0.0% | 0.0% | 0.2% |
| Other | 0.0% | 0.1% | 0.4% |
| Two or More Races | 2.3% | 4.6% | 3.2% |
| Hispanic | 0.9% | 27.7% | 18.4% |
| space2 | | | |
| Marriage & Family | | | |
| | Lyndon, KS | Emporia, KS | United States |
| Married Population | 45.8% | 44.7% | 49.8% |
| Currently Married | 45.5% | 43.4% | 48.0% |
| Married but Separated | 0.4% | 1.3% | 1.8% |
| Single Population | 54.2% | 55.3% | 50.2% |
| Never Married | 28.7% | 41.9% | 33.8% |
| Divorced | 19.2% | 9.5% | 10.8% |
| Widowed | 6.3% | 3.9% | 5.6% |
| space5 | | | |
| Household Size | 2.96 | 2.32 | 2.60 |
| Households | 369 | 9,943 | 124,010,992 |
| Family Households | 257 | 5,262 | 80,755,759 |
| Married couple, w/children | 26.1% | 32.0% | 30.5% |
| Married couple, no children | 44.0% | 46.1% | 42.9% |
| Non Family Households | 112 | 4,681 | 43,255,233 |
| Single householder, w/children | 17.9% | 17.0% | 15.8% |
| Single householder, no children | 12.1% | 4.9% | 10.8% |