| | Errol, NH | Lancaster, NH | United States |
| Population | 262 | 3,215 | 329,725,481 |
| Female Population | 45.4% | 50.2% | 50.5% |
| Male Population | 54.6% | 49.8% | 49.5% |
| Median Age | 62 | 38.3 | 38.4 |
| space3 | | | |
| Population - 2010 | 290 | 3,498 | 309,327,143 |
| Population - 2000 | 298 | 3,280 | 285,036,114 |
| Population - 1990 | 292 | 3,522 | 251,960,433 |
| Pop. 2000 to Now | -11.7% | -1.4% | 15.6% |
| Pop. 1990 to Now | -9.9% | -8.2% | 30.8% |
| space4 | | | |
| Population Density | 4.3 | 64.5 | 93.4 |
| Land Area | 60.6 | 49.8 | 3,531,905.4 |
| Water Area | 9.1 | 0.9 | 264,836.8 |
| space | | | |
| Est. Total Population By Age | | | |
| | Errol, NH | Lancaster, NH | United States |
| Age 0 to 4 | 0.0% | 5.5% | 5.9% |
| Age 5 to 9 | 0.4% | 5.6% | 6.1% |
| Age 10 to 14 | 8.0% | 8.5% | 6.6% |
| Age 15 to 17 | 1.5% | 5.7% | 3.9% |
| Age 18 to 20 | 1.5% | 4.2% | 4.0% |
| Age 21 to 24 | 0.0% | 4.8% | 5.2% |
| Age 25 to 34 | 1.9% | 12.1% | 13.8% |
| Age 35 to 44 | 11.8% | 10.6% | 12.9% |
| Age 45 to 54 | 5.0% | 10.9% | 12.6% |
| Age 55 to 59 | 13.7% | 4.9% | 6.7% |
| Age 60 to 64 | 18.3% | 6.5% | 6.3% |
| Age 65 to 74 | 22.1% | 10.5% | 9.6% |
| Age 75 to 84 | 14.1% | 7.5% | 4.5% |
| Age 85 and over | 1.5% | 2.8% | 1.9% |
| space1 | | | |
| Race | | | |
| | Errol, NH | Lancaster, NH | United States |
| White | 100.0% | 95.3% | 59.4% |
| Black | 0.0% | 0.1% | 12.2% |
| Asian | 0.0% | 0.0% | 5.6% |
| Native American | 0.0% | 0.0% | 0.6% |
| Hawaiian, Pacific Islander | 0.0% | 0.0% | 0.2% |
| Other | 0.0% | 0.0% | 0.4% |
| Two or More Races | 0.0% | 3.7% | 3.2% |
| Hispanic | 0.0% | 0.9% | 18.4% |
| space2 | | | |
| Marriage & Family | | | |
| | Errol, NH | Lancaster, NH | United States |
| Married Population | 70.0% | 39.4% | 49.8% |
| Currently Married | 67.9% | 38.4% | 48.0% |
| Married but Separated | 2.1% | 1.0% | 1.8% |
| Single Population | 30.0% | 60.6% | 50.2% |
| Never Married | 16.3% | 33.9% | 33.8% |
| Divorced | 7.1% | 18.1% | 10.8% |
| Widowed | 6.7% | 8.5% | 5.6% |
| space5 | | | |
| Household Size | 2.03 | 2.43 | 2.60 |
| Households | 129 | 1,276 | 124,010,992 |
| Family Households | 90 | 726 | 80,755,759 |
| Married couple, w/children | 5.6% | 23.7% | 30.5% |
| Married couple, no children | 85.6% | 41.9% | 42.9% |
| Non Family Households | 39 | 550 | 43,255,233 |
| Single householder, w/children | 4.4% | 23.0% | 15.8% |
| Single householder, no children | 4.4% | 11.4% | 10.8% |