| | Firth, NE | Chadron, NE | United States |
| Population | 452 | 5,376 | 329,725,481 |
| Female Population | 46.5% | 52.8% | 50.5% |
| Male Population | 53.5% | 47.2% | 49.5% |
| Median Age | 37.9 | 27.8 | 38.4 |
| space3 | | | |
| Population - 2010 | 584 | 5,843 | 309,327,143 |
| Population - 2000 | 564 | 5,634 | 285,036,114 |
| Population - 1990 | 471 | 5,588 | 251,960,433 |
| Pop. 2000 to Now | 9.8% | -6.8% | 15.6% |
| Pop. 1990 to Now | 31.4% | -6.1% | 30.8% |
| space4 | | | |
| Population Density | 1,602.8 | 1,377.8 | 93.4 |
| Land Area | 0.3 | 3.9 | 3,531,905.4 |
| Water Area | 0.0 | 0.0 | 264,836.8 |
| space | | | |
| Est. Total Population By Age | | | |
| | Firth, NE | Chadron, NE | United States |
| Age 0 to 4 | 8.4% | 6.3% | 5.9% |
| Age 5 to 9 | 6.4% | 4.8% | 6.1% |
| Age 10 to 14 | 7.3% | 4.5% | 6.6% |
| Age 15 to 17 | 5.3% | 2.9% | 3.9% |
| Age 18 to 20 | 1.5% | 15.5% | 4.0% |
| Age 21 to 24 | 3.3% | 11.5% | 5.2% |
| Age 25 to 34 | 10.8% | 10.8% | 13.8% |
| Age 35 to 44 | 17.3% | 9.6% | 12.9% |
| Age 45 to 54 | 13.7% | 8.1% | 12.6% |
| Age 55 to 59 | 8.4% | 7.2% | 6.7% |
| Age 60 to 64 | 3.5% | 5.8% | 6.3% |
| Age 65 to 74 | 7.1% | 6.1% | 9.6% |
| Age 75 to 84 | 4.2% | 5.4% | 4.5% |
| Age 85 and over | 2.7% | 1.5% | 1.9% |
| space1 | | | |
| Race | | | |
| | Firth, NE | Chadron, NE | United States |
| White | 85.4% | 84.7% | 59.4% |
| Black | 0.0% | 7.2% | 12.2% |
| Asian | 1.8% | 0.7% | 5.6% |
| Native American | 0.0% | 0.6% | 0.6% |
| Hawaiian, Pacific Islander | 0.0% | 0.0% | 0.2% |
| Other | 0.9% | 0.0% | 0.4% |
| Two or More Races | 1.1% | 3.1% | 3.2% |
| Hispanic | 10.8% | 3.8% | 18.4% |
| space2 | | | |
| Marriage & Family | | | |
| | Firth, NE | Chadron, NE | United States |
| Married Population | 67.9% | 40.1% | 49.8% |
| Currently Married | 66.8% | 39.6% | 48.0% |
| Married but Separated | 1.1% | 0.5% | 1.8% |
| Single Population | 32.1% | 59.9% | 50.2% |
| Never Married | 19.6% | 48.4% | 33.8% |
| Divorced | 6.8% | 6.7% | 10.8% |
| Widowed | 5.7% | 4.8% | 5.6% |
| space5 | | | |
| Household Size | 2.32 | 2.15 | 2.60 |
| Households | 195 | 2,119 | 124,010,992 |
| Family Households | 139 | 1,095 | 80,755,759 |
| Married couple, w/children | 33.8% | 37.2% | 30.5% |
| Married couple, no children | 57.6% | 42.4% | 42.9% |
| Non Family Households | 56 | 1,024 | 43,255,233 |
| Single householder, w/children | 5.8% | 12.1% | 15.8% |
| Single householder, no children | 2.9% | 8.4% | 10.8% |