| | Kentwood, MI | Allegan, MI | United States |
| Population | 53,884 | 5,165 | 329,725,481 |
| Female Population | 51.5% | 49.5% | 50.5% |
| Male Population | 48.5% | 50.6% | 49.5% |
| Median Age | 34.6 | 31.8 | 38.4 |
| space3 | | | |
| Population - 2010 | 48,731 | 4,996 | 309,327,143 |
| Population - 2000 | 45,255 | 4,838 | 285,036,114 |
| Population - 1990 | 37,826 | 4,547 | 251,960,433 |
| Pop. 2000 to Now | 14.3% | 3.7% | 15.6% |
| Pop. 1990 to Now | 36.7% | 10.3% | 30.8% |
| space4 | | | |
| Population Density | 2,576.5 | 1,343.0 | 93.4 |
| Land Area | 20.9 | 3.8 | 3,531,905.4 |
| Water Area | 0.1 | 0.4 | 264,836.8 |
| space | | | |
| Est. Total Population By Age | | | |
| | Kentwood, MI | Allegan, MI | United States |
| Age 0 to 4 | 7.0% | 4.7% | 5.9% |
| Age 5 to 9 | 8.8% | 8.0% | 6.1% |
| Age 10 to 14 | 5.6% | 7.4% | 6.6% |
| Age 15 to 17 | 3.2% | 3.3% | 3.9% |
| Age 18 to 20 | 2.6% | 4.0% | 4.0% |
| Age 21 to 24 | 4.9% | 14.4% | 5.2% |
| Age 25 to 34 | 18.5% | 14.2% | 13.8% |
| Age 35 to 44 | 12.7% | 8.8% | 12.9% |
| Age 45 to 54 | 10.8% | 8.1% | 12.6% |
| Age 55 to 59 | 5.5% | 7.8% | 6.7% |
| Age 60 to 64 | 6.1% | 5.3% | 6.3% |
| Age 65 to 74 | 8.1% | 7.3% | 9.6% |
| Age 75 to 84 | 4.0% | 4.8% | 4.5% |
| Age 85 and over | 2.1% | 1.9% | 1.9% |
| space1 | | | |
| Race | | | |
| | Kentwood, MI | Allegan, MI | United States |
| White | 58.1% | 84.1% | 59.4% |
| Black | 18.1% | 5.3% | 12.2% |
| Asian | 9.1% | 1.5% | 5.6% |
| Native American | 0.2% | 0.7% | 0.6% |
| Hawaiian, Pacific Islander | 0.1% | 0.0% | 0.2% |
| Other | 0.1% | 0.4% | 0.4% |
| Two or More Races | 4.7% | 3.0% | 3.2% |
| Hispanic | 9.7% | 5.0% | 18.4% |
| space2 | | | |
| Marriage & Family | | | |
| | Kentwood, MI | Allegan, MI | United States |
| Married Population | 47.2% | 46.1% | 49.8% |
| Currently Married | 46.4% | 44.2% | 48.0% |
| Married but Separated | 0.8% | 1.9% | 1.8% |
| Single Population | 52.8% | 53.9% | 50.2% |
| Never Married | 35.1% | 36.5% | 33.8% |
| Divorced | 12.7% | 11.3% | 10.8% |
| Widowed | 5.0% | 6.1% | 5.6% |
| space5 | | | |
| Household Size | 2.46 | 2.54 | 2.60 |
| Households | 21,720 | 1,939 | 124,010,992 |
| Family Households | 13,217 | 1,264 | 80,755,759 |
| Married couple, w/children | 31.1% | 31.6% | 30.5% |
| Married couple, no children | 37.9% | 37.9% | 42.9% |
| Non Family Households | 8,503 | 675 | 43,255,233 |
| Single householder, w/children | 20.5% | 17.3% | 15.8% |
| Single householder, no children | 10.6% | 13.2% | 10.8% |