| | Lower Nazareth, PA | Bethlehem, PA | United States |
| Population | 6,814 | 75,599 | 329,725,481 |
| Female Population | 47.7% | 52.2% | 50.5% |
| Male Population | 52.3% | 47.9% | 49.5% |
| Median Age | 42.2 | 36.4 | 38.4 |
| space3 | | | |
| Population - 2010 | 5,693 | 74,974 | 309,327,143 |
| Population - 2000 | 5,259 | 71,329 | 285,036,114 |
| Population - 1990 | 4,483 | 71,428 | 251,960,433 |
| Pop. 2000 to Now | 26.5% | 5.8% | 15.6% |
| Pop. 1990 to Now | 48.4% | 5.7% | 30.8% |
| space4 | | | |
| Population Density | 504.9 | 3,955.0 | 93.4 |
| Land Area | 13.5 | 19.1 | 3,531,905.4 |
| Water Area | 0.1 | 0.3 | 264,836.8 |
| space | | | |
| Est. Total Population By Age | | | |
| | Lower Nazareth, PA | Bethlehem, PA | United States |
| Age 0 to 4 | 8.6% | 5.0% | 5.9% |
| Age 5 to 9 | 4.8% | 4.4% | 6.1% |
| Age 10 to 14 | 5.8% | 5.2% | 6.6% |
| Age 15 to 17 | 5.6% | 3.0% | 3.9% |
| Age 18 to 20 | 2.0% | 8.7% | 4.0% |
| Age 21 to 24 | 3.9% | 7.5% | 5.2% |
| Age 25 to 34 | 7.8% | 14.6% | 13.8% |
| Age 35 to 44 | 13.9% | 11.7% | 12.9% |
| Age 45 to 54 | 15.1% | 10.6% | 12.6% |
| Age 55 to 59 | 10.3% | 5.5% | 6.7% |
| Age 60 to 64 | 6.3% | 5.8% | 6.3% |
| Age 65 to 74 | 9.9% | 9.8% | 9.6% |
| Age 75 to 84 | 5.0% | 5.2% | 4.5% |
| Age 85 and over | 1.0% | 3.0% | 1.9% |
| space1 | | | |
| Race | | | |
| | Lower Nazareth, PA | Bethlehem, PA | United States |
| White | 82.8% | 55.8% | 59.4% |
| Black | 2.5% | 8.2% | 12.2% |
| Asian | 6.4% | 2.9% | 5.6% |
| Native American | 0.0% | 0.0% | 0.6% |
| Hawaiian, Pacific Islander | 0.0% | 0.0% | 0.2% |
| Other | 0.0% | 0.4% | 0.4% |
| Two or More Races | 0.6% | 2.6% | 3.2% |
| Hispanic | 7.7% | 30.1% | 18.4% |
| space2 | | | |
| Marriage & Family | | | |
| | Lower Nazareth, PA | Bethlehem, PA | United States |
| Married Population | 65.3% | 37.6% | 49.8% |
| Currently Married | 64.8% | 35.4% | 48.0% |
| Married but Separated | 0.5% | 2.2% | 1.8% |
| Single Population | 34.7% | 62.4% | 50.2% |
| Never Married | 23.2% | 45.0% | 33.8% |
| Divorced | 7.4% | 10.9% | 10.8% |
| Widowed | 4.1% | 6.6% | 5.6% |
| space5 | | | |
| Household Size | 2.83 | 2.33 | 2.60 |
| Households | 2,405 | 29,874 | 124,010,992 |
| Family Households | 1,839 | 16,673 | 80,755,759 |
| Married couple, w/children | 40.6% | 19.4% | 30.5% |
| Married couple, no children | 50.7% | 43.5% | 42.9% |
| Non Family Households | 566 | 13,201 | 43,255,233 |
| Single householder, w/children | 3.9% | 21.5% | 15.8% |
| Single householder, no children | 4.8% | 15.6% | 10.8% |