| | Irondale, MO | Lebanon, MO | United States |
| Population | 562 | 14,880 | 329,725,481 |
| Female Population | 39.2% | 52.1% | 50.5% |
| Male Population | 60.9% | 47.9% | 49.5% |
| Median Age | 35.1 | 34.5 | 38.4 |
| space3 | | | |
| Population - 2010 | 442 | 14,528 | 309,327,143 |
| Population - 2000 | 437 | 12,155 | 285,036,114 |
| Population - 1990 | 474 | 9,983 | 251,960,433 |
| Pop. 2000 to Now | 0.2% | 22.4% | 15.6% |
| Pop. 1990 to Now | -7.6% | 49.1% | 30.8% |
| space4 | | | |
| Population Density | 1,054.4 | 1,016.3 | 93.4 |
| Land Area | 0.5 | 14.6 | 3,531,905.4 |
| Water Area | 0.0 | 0.1 | 264,836.8 |
| space | | | |
| Est. Total Population By Age | | | |
| | Irondale, MO | Lebanon, MO | United States |
| Age 0 to 4 | 8.4% | 8.4% | 5.9% |
| Age 5 to 9 | 10.0% | 7.9% | 6.1% |
| Age 10 to 14 | 8.0% | 7.6% | 6.6% |
| Age 15 to 17 | 8.7% | 4.8% | 3.9% |
| Age 18 to 20 | 4.1% | 3.4% | 4.0% |
| Age 21 to 24 | 0.0% | 3.6% | 5.2% |
| Age 25 to 34 | 10.3% | 15.4% | 13.8% |
| Age 35 to 44 | 27.8% | 12.3% | 12.9% |
| Age 45 to 54 | 8.7% | 12.0% | 12.6% |
| Age 55 to 59 | 5.7% | 6.4% | 6.7% |
| Age 60 to 64 | 1.6% | 3.8% | 6.3% |
| Age 65 to 74 | 3.7% | 7.0% | 9.6% |
| Age 75 to 84 | 2.8% | 4.9% | 4.5% |
| Age 85 and over | 0.2% | 2.5% | 1.9% |
| space1 | | | |
| Race | | | |
| | Irondale, MO | Lebanon, MO | United States |
| White | 88.3% | 87.5% | 59.4% |
| Black | 0.0% | 1.1% | 12.2% |
| Asian | 3.9% | 0.9% | 5.6% |
| Native American | 0.0% | 0.2% | 0.6% |
| Hawaiian, Pacific Islander | 0.0% | 0.0% | 0.2% |
| Other | 0.0% | 0.0% | 0.4% |
| Two or More Races | 7.8% | 4.6% | 3.2% |
| Hispanic | 0.0% | 5.6% | 18.4% |
| space2 | | | |
| Marriage & Family | | | |
| | Irondale, MO | Lebanon, MO | United States |
| Married Population | 45.2% | 48.2% | 49.8% |
| Currently Married | 38.9% | 44.7% | 48.0% |
| Married but Separated | 6.3% | 3.5% | 1.8% |
| Single Population | 54.8% | 51.8% | 50.2% |
| Never Married | 31.6% | 25.3% | 33.8% |
| Divorced | 21.7% | 16.6% | 10.8% |
| Widowed | 1.4% | 10.0% | 5.6% |
| space5 | | | |
| Household Size | 2.64 | 2.44 | 2.60 |
| Households | 213 | 5,979 | 124,010,992 |
| Family Households | 147 | 3,762 | 80,755,759 |
| Married couple, w/children | 49.7% | 34.8% | 30.5% |
| Married couple, no children | 14.3% | 29.0% | 42.9% |
| Non Family Households | 66 | 2,217 | 43,255,233 |
| Single householder, w/children | 26.5% | 28.5% | 15.8% |
| Single householder, no children | 9.5% | 7.7% | 10.8% |