| | Princeton, MA | Royalston, MA | United States |
| Population | 3,502 | 1,461 | 329,725,481 |
| Female Population | 49.0% | 42.4% | 50.5% |
| Male Population | 51.0% | 57.6% | 49.5% |
| Median Age | 49.1 | 48.2 | 38.4 |
| space3 | | | |
| Population - 2010 | 3,419 | 1,259 | 309,327,143 |
| Population - 2000 | 3,353 | 1,254 | 285,036,114 |
| Population - 1990 | 3,189 | 1,147 | 251,960,433 |
| Pop. 2000 to Now | 4.0% | 1.9% | 15.6% |
| Pop. 1990 to Now | 9.3% | 11.4% | 30.8% |
| space4 | | | |
| Population Density | 98.9 | 35.0 | 93.4 |
| Land Area | 35.4 | 41.8 | 3,531,905.4 |
| Water Area | 0.4 | 0.7 | 264,836.8 |
| space | | | |
| Est. Total Population By Age | | | |
| | Princeton, MA | Royalston, MA | United States |
| Age 0 to 4 | 3.5% | 6.0% | 5.9% |
| Age 5 to 9 | 6.8% | 8.2% | 6.1% |
| Age 10 to 14 | 6.3% | 3.8% | 6.6% |
| Age 15 to 17 | 3.3% | 4.5% | 3.9% |
| Age 18 to 20 | 3.3% | 0.8% | 4.0% |
| Age 21 to 24 | 2.8% | 5.1% | 5.2% |
| Age 25 to 34 | 8.1% | 9.9% | 13.8% |
| Age 35 to 44 | 10.9% | 7.5% | 12.9% |
| Age 45 to 54 | 14.6% | 17.9% | 12.6% |
| Age 55 to 59 | 10.3% | 7.2% | 6.7% |
| Age 60 to 64 | 9.5% | 10.2% | 6.3% |
| Age 65 to 74 | 14.3% | 14.6% | 9.6% |
| Age 75 to 84 | 5.5% | 3.7% | 4.5% |
| Age 85 and over | 1.0% | 0.7% | 1.9% |
| space1 | | | |
| Race | | | |
| | Princeton, MA | Royalston, MA | United States |
| White | 91.0% | 98.8% | 59.4% |
| Black | 0.3% | 0.0% | 12.2% |
| Asian | 0.0% | 0.2% | 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 | 7.1% | 1.0% | 3.2% |
| Hispanic | 1.6% | 0.0% | 18.4% |
| space2 | | | |
| Marriage & Family | | | |
| | Princeton, MA | Royalston, MA | United States |
| Married Population | 64.5% | 60.8% | 49.8% |
| Currently Married | 64.5% | 59.5% | 48.0% |
| Married but Separated | 0.0% | 1.3% | 1.8% |
| Single Population | 35.5% | 39.2% | 50.2% |
| Never Married | 20.2% | 26.9% | 33.8% |
| Divorced | 10.2% | 7.6% | 10.8% |
| Widowed | 5.1% | 4.8% | 5.6% |
| space5 | | | |
| Household Size | 2.67 | 2.65 | 2.60 |
| Households | 1,298 | 551 | 124,010,992 |
| Family Households | 1,039 | 393 | 80,755,759 |
| Married couple, w/children | 28.2% | 23.7% | 30.5% |
| Married couple, no children | 56.3% | 61.6% | 42.9% |
| Non Family Households | 259 | 158 | 43,255,233 |
| Single householder, w/children | 5.9% | 11.5% | 15.8% |
| Single householder, no children | 9.6% | 3.3% | 10.8% |