| | Oakland, IA | Manning, IA | United States |
| Population | 1,761 | 1,510 | 329,725,481 |
| Female Population | 48.0% | 48.5% | 50.5% |
| Male Population | 52.0% | 51.5% | 49.5% |
| Median Age | 36.6 | 38.1 | 38.4 |
| space3 | | | |
| Population - 2010 | 1,529 | 1,516 | 309,327,143 |
| Population - 2000 | 1,487 | 1,490 | 285,036,114 |
| Population - 1990 | 1,496 | 1,484 | 251,960,433 |
| Pop. 2000 to Now | 0.3% | -5.8% | 15.6% |
| Pop. 1990 to Now | -0.3% | -5.5% | 30.8% |
| space4 | | | |
| Population Density | 1,237.5 | 607.4 | 93.4 |
| Land Area | 1.4 | 2.5 | 3,531,905.4 |
| Water Area | 0.2 | 0.0 | 264,836.8 |
| space | | | |
| Est. Total Population By Age | | | |
| | Oakland, IA | Manning, IA | United States |
| Age 0 to 4 | 7.7% | 5.8% | 5.9% |
| Age 5 to 9 | 8.6% | 9.1% | 6.1% |
| Age 10 to 14 | 4.4% | 3.4% | 6.6% |
| Age 15 to 17 | 5.3% | 2.0% | 3.9% |
| Age 18 to 20 | 2.7% | 2.9% | 4.0% |
| Age 21 to 24 | 6.5% | 3.2% | 5.2% |
| Age 25 to 34 | 13.3% | 17.5% | 13.8% |
| Age 35 to 44 | 8.0% | 11.3% | 12.9% |
| Age 45 to 54 | 9.7% | 12.6% | 12.6% |
| Age 55 to 59 | 8.6% | 5.8% | 6.7% |
| Age 60 to 64 | 7.2% | 5.0% | 6.3% |
| Age 65 to 74 | 10.2% | 8.6% | 9.6% |
| Age 75 to 84 | 3.7% | 8.9% | 4.5% |
| Age 85 and over | 4.0% | 3.8% | 1.9% |
| space1 | | | |
| Race | | | |
| | Oakland, IA | Manning, IA | United States |
| White | 81.4% | 87.9% | 59.4% |
| Black | 0.1% | 0.1% | 12.2% |
| Asian | 0.5% | 3.1% | 5.6% |
| Native American | 0.2% | 0.0% | 0.6% |
| Hawaiian, Pacific Islander | 0.0% | 0.0% | 0.2% |
| Other | 0.0% | 3.7% | 0.4% |
| Two or More Races | 6.9% | 4.2% | 3.2% |
| Hispanic | 11.0% | 1.0% | 18.4% |
| space2 | | | |
| Marriage & Family | | | |
| | Oakland, IA | Manning, IA | United States |
| Married Population | 42.5% | 52.5% | 49.8% |
| Currently Married | 40.5% | 51.7% | 48.0% |
| Married but Separated | 1.9% | 0.7% | 1.8% |
| Single Population | 57.5% | 47.5% | 50.2% |
| Never Married | 31.2% | 25.7% | 33.8% |
| Divorced | 19.1% | 13.5% | 10.8% |
| Widowed | 7.3% | 8.3% | 5.6% |
| space5 | | | |
| Household Size | 2.77 | 2.03 | 2.60 |
| Households | 623 | 716 | 124,010,992 |
| Family Households | 418 | 362 | 80,755,759 |
| Married couple, w/children | 21.8% | 27.6% | 30.5% |
| Married couple, no children | 40.9% | 58.3% | 42.9% |
| Non Family Households | 205 | 354 | 43,255,233 |
| Single householder, w/children | 25.8% | 8.8% | 15.8% |
| Single householder, no children | 11.5% | 5.2% | 10.8% |