| | Hatfield, MA | Sterling, MA | United States |
| Population | 3,315 | 8,015 | 329,725,481 |
| Female Population | 52.1% | 52.4% | 50.5% |
| Male Population | 47.9% | 47.6% | 49.5% |
| Median Age | 45 | 49.9 | 38.4 |
| space3 | | | |
| Population - 2010 | 3,259 | 7,807 | 309,327,143 |
| Population - 2000 | 3,249 | 7,257 | 285,036,114 |
| Population - 1990 | 3,184 | 6,481 | 251,960,433 |
| Pop. 2000 to Now | -0.2% | 12.5% | 15.6% |
| Pop. 1990 to Now | 1.9% | 26.0% | 30.8% |
| space4 | | | |
| Population Density | 208.4 | 261.6 | 93.4 |
| Land Area | 15.9 | 30.6 | 3,531,905.4 |
| Water Area | 0.9 | 1.1 | 264,836.8 |
| space | | | |
| Est. Total Population By Age | | | |
| | Hatfield, MA | Sterling, MA | United States |
| Age 0 to 4 | 5.2% | 4.5% | 5.9% |
| Age 5 to 9 | 2.1% | 2.7% | 6.1% |
| Age 10 to 14 | 6.4% | 9.0% | 6.6% |
| Age 15 to 17 | 2.9% | 5.5% | 3.9% |
| Age 18 to 20 | 5.3% | 1.5% | 4.0% |
| Age 21 to 24 | 5.6% | 1.7% | 5.2% |
| Age 25 to 34 | 14.2% | 8.3% | 13.8% |
| Age 35 to 44 | 8.4% | 9.2% | 12.9% |
| Age 45 to 54 | 9.5% | 17.2% | 12.6% |
| Age 55 to 59 | 8.5% | 13.2% | 6.7% |
| Age 60 to 64 | 8.7% | 7.1% | 6.3% |
| Age 65 to 74 | 14.3% | 14.2% | 9.6% |
| Age 75 to 84 | 6.7% | 5.2% | 4.5% |
| Age 85 and over | 2.2% | 0.8% | 1.9% |
| space1 | | | |
| Race | | | |
| | Hatfield, MA | Sterling, MA | United States |
| White | 88.6% | 93.9% | 59.4% |
| Black | 0.0% | 1.0% | 12.2% |
| Asian | 1.5% | 0.4% | 5.6% |
| Native American | 0.0% | 0.2% | 0.6% |
| Hawaiian, Pacific Islander | 0.0% | 0.0% | 0.2% |
| Other | 0.6% | 0.3% | 0.4% |
| Two or More Races | 3.1% | 0.9% | 3.2% |
| Hispanic | 6.1% | 3.3% | 18.4% |
| space2 | | | |
| Marriage & Family | | | |
| | Hatfield, MA | Sterling, MA | United States |
| Married Population | 48.7% | 59.3% | 49.8% |
| Currently Married | 48.3% | 58.3% | 48.0% |
| Married but Separated | 0.4% | 1.1% | 1.8% |
| Single Population | 51.3% | 40.7% | 50.2% |
| Never Married | 33.4% | 26.4% | 33.8% |
| Divorced | 9.6% | 8.6% | 10.8% |
| Widowed | 8.2% | 5.7% | 5.6% |
| space5 | | | |
| Household Size | 2.22 | 2.42 | 2.60 |
| Households | 1,490 | 3,248 | 124,010,992 |
| Family Households | 905 | 2,403 | 80,755,759 |
| Married couple, w/children | 25.4% | 32.7% | 30.5% |
| Married couple, no children | 47.2% | 48.5% | 42.9% |
| Non Family Households | 585 | 845 | 43,255,233 |
| Single householder, w/children | 16.8% | 11.3% | 15.8% |
| Single householder, no children | 10.6% | 7.5% | 10.8% |