| | North Royalton, OH | Parma, OH | United States |
| Population | 31,150 | 80,880 | 329,725,481 |
| Female Population | 51.1% | 50.8% | 50.5% |
| Male Population | 49.0% | 49.2% | 49.5% |
| Median Age | 43.8 | 42.5 | 38.4 |
| space3 | | | |
| Population - 2010 | 30,446 | 81,483 | 309,327,143 |
| Population - 2000 | 28,648 | 85,655 | 285,036,114 |
| Population - 1990 | 23,197 | 87,876 | 251,960,433 |
| Pop. 2000 to Now | 4.6% | -9.5% | 15.6% |
| Pop. 1990 to Now | 29.1% | -11.7% | 30.8% |
| space4 | | | |
| Population Density | 1,461.3 | 4,040.6 | 93.4 |
| Land Area | 21.3 | 20.0 | 3,531,905.4 |
| Water Area | 0.0 | 0.0 | 264,836.8 |
| space | | | |
| Est. Total Population By Age | | | |
| | North Royalton, OH | Parma, OH | United States |
| Age 0 to 4 | 4.0% | 5.6% | 5.9% |
| Age 5 to 9 | 5.3% | 4.3% | 6.1% |
| Age 10 to 14 | 6.1% | 5.1% | 6.6% |
| Age 15 to 17 | 2.8% | 3.0% | 3.9% |
| Age 18 to 20 | 3.0% | 3.9% | 4.0% |
| Age 21 to 24 | 5.5% | 5.0% | 5.2% |
| Age 25 to 34 | 13.7% | 15.6% | 13.8% |
| Age 35 to 44 | 10.5% | 10.5% | 12.9% |
| Age 45 to 54 | 15.1% | 12.8% | 12.6% |
| Age 55 to 59 | 6.2% | 7.5% | 6.7% |
| Age 60 to 64 | 8.4% | 7.2% | 6.3% |
| Age 65 to 74 | 12.2% | 11.3% | 9.6% |
| Age 75 to 84 | 5.3% | 5.9% | 4.5% |
| Age 85 and over | 1.8% | 2.3% | 1.9% |
| space1 | | | |
| Race | | | |
| | North Royalton, OH | Parma, OH | United States |
| White | 85.9% | 82.2% | 59.4% |
| Black | 2.9% | 4.7% | 12.2% |
| Asian | 4.6% | 2.4% | 5.6% |
| Native American | 0.2% | 0.1% | 0.6% |
| Hawaiian, Pacific Islander | 0.0% | 0.0% | 0.2% |
| Other | 0.0% | 0.3% | 0.4% |
| Two or More Races | 2.9% | 3.3% | 3.2% |
| Hispanic | 3.5% | 7.1% | 18.4% |
| space2 | | | |
| Marriage & Family | | | |
| | North Royalton, OH | Parma, OH | United States |
| Married Population | 55.8% | 44.7% | 49.8% |
| Currently Married | 55.2% | 43.1% | 48.0% |
| Married but Separated | 0.6% | 1.6% | 1.8% |
| Single Population | 44.2% | 55.3% | 50.2% |
| Never Married | 28.4% | 35.8% | 33.8% |
| Divorced | 10.0% | 12.9% | 10.8% |
| Widowed | 5.8% | 6.6% | 5.6% |
| space5 | | | |
| Household Size | 2.28 | 2.34 | 2.60 |
| Households | 13,507 | 34,110 | 124,010,992 |
| Family Households | 8,672 | 20,850 | 80,755,759 |
| Married couple, w/children | 28.5% | 21.8% | 30.5% |
| Married couple, no children | 51.7% | 45.8% | 42.9% |
| Non Family Households | 4,835 | 13,260 | 43,255,233 |
| Single householder, w/children | 11.6% | 15.5% | 15.8% |
| Single householder, no children | 8.2% | 16.9% | 10.8% |