| | Maplewood, NJ | North Plainfield, NJ | United States |
| Population | 25,420 | 22,635 | 329,725,481 |
| Female Population | 49.0% | 52.6% | 50.5% |
| Male Population | 51.1% | 47.4% | 49.5% |
| Median Age | 39.2 | 36.6 | 38.4 |
| space3 | | | |
| Population - 2010 | 23,832 | 21,784 | 309,327,143 |
| Population - 2000 | 23,868 | 21,103 | 285,036,114 |
| Population - 1990 | 21,652 | 18,820 | 251,960,433 |
| Pop. 2000 to Now | 8.9% | 0.7% | 15.6% |
| Pop. 1990 to Now | 20.0% | 12.9% | 30.8% |
| space4 | | | |
| Population Density | 6,556.6 | 8,063.8 | 93.4 |
| Land Area | 3.9 | 2.8 | 3,531,905.4 |
| Water Area | 0.0 | 0.0 | 264,836.8 |
| space | | | |
| Est. Total Population By Age | | | |
| | Maplewood, NJ | North Plainfield, NJ | United States |
| Age 0 to 4 | 7.2% | 7.6% | 5.9% |
| Age 5 to 9 | 8.3% | 6.0% | 6.1% |
| Age 10 to 14 | 8.3% | 6.2% | 6.6% |
| Age 15 to 17 | 4.1% | 3.3% | 3.9% |
| Age 18 to 20 | 3.3% | 3.6% | 4.0% |
| Age 21 to 24 | 3.7% | 5.2% | 5.2% |
| Age 25 to 34 | 10.2% | 15.0% | 13.8% |
| Age 35 to 44 | 14.7% | 14.2% | 12.9% |
| Age 45 to 54 | 16.0% | 12.1% | 12.6% |
| Age 55 to 59 | 7.7% | 8.0% | 6.7% |
| Age 60 to 64 | 5.8% | 7.5% | 6.3% |
| Age 65 to 74 | 6.2% | 7.6% | 9.6% |
| Age 75 to 84 | 3.3% | 2.2% | 4.5% |
| Age 85 and over | 1.2% | 1.3% | 1.9% |
| space1 | | | |
| Race | | | |
| | Maplewood, NJ | North Plainfield, NJ | United States |
| White | 50.3% | 22.9% | 59.4% |
| Black | 33.3% | 21.1% | 12.2% |
| Asian | 3.4% | 4.3% | 5.6% |
| Native American | 0.5% | 0.1% | 0.6% |
| Hawaiian, Pacific Islander | 0.0% | 0.0% | 0.2% |
| Other | 1.6% | 1.2% | 0.4% |
| Two or More Races | 2.6% | 1.0% | 3.2% |
| Hispanic | 8.3% | 49.5% | 18.4% |
| space2 | | | |
| Marriage & Family | | | |
| | Maplewood, NJ | North Plainfield, NJ | United States |
| Married Population | 58.1% | 46.3% | 49.8% |
| Currently Married | 56.9% | 43.8% | 48.0% |
| Married but Separated | 1.2% | 2.5% | 1.8% |
| Single Population | 41.9% | 53.7% | 50.2% |
| Never Married | 31.0% | 42.8% | 33.8% |
| Divorced | 6.3% | 7.7% | 10.8% |
| Widowed | 4.5% | 3.2% | 5.6% |
| space5 | | | |
| Household Size | 3.07 | 2.82 | 2.60 |
| Households | 8,264 | 8,004 | 124,010,992 |
| Family Households | 6,416 | 5,599 | 80,755,759 |
| Married couple, w/children | 47.8% | 30.6% | 30.5% |
| Married couple, no children | 32.4% | 32.3% | 42.9% |
| Non Family Households | 1,848 | 2,405 | 43,255,233 |
| Single householder, w/children | 14.2% | 12.4% | 15.8% |
| Single householder, no children | 5.7% | 24.7% | 10.8% |