| | Callender, IA | Leon, IA | United States |
| Population | 429 | 1,716 | 329,725,481 |
| Female Population | 51.5% | 50.4% | 50.5% |
| Male Population | 48.5% | 49.6% | 49.5% |
| Median Age | 28.9 | 36.8 | 38.4 |
| space3 | | | |
| Population - 2010 | 373 | 1,968 | 309,327,143 |
| Population - 2000 | 424 | 1,983 | 285,036,114 |
| Population - 1990 | 384 | 2,047 | 251,960,433 |
| Pop. 2000 to Now | -18.4% | -8.8% | 15.6% |
| Pop. 1990 to Now | -9.9% | -11.7% | 30.8% |
| space4 | | | |
| Population Density | 818.7 | 541.0 | 93.4 |
| Land Area | 0.5 | 3.2 | 3,531,905.4 |
| Water Area | 0.0 | 0.0 | 264,836.8 |
| space | | | |
| Est. Total Population By Age | | | |
| | Callender, IA | Leon, IA | United States |
| Age 0 to 4 | 10.7% | 4.4% | 5.9% |
| Age 5 to 9 | 4.7% | 5.3% | 6.1% |
| Age 10 to 14 | 14.0% | 9.2% | 6.6% |
| Age 15 to 17 | 4.9% | 4.6% | 3.9% |
| Age 18 to 20 | 3.3% | 0.9% | 4.0% |
| Age 21 to 24 | 6.1% | 15.6% | 5.2% |
| Age 25 to 34 | 10.7% | 6.1% | 13.8% |
| Age 35 to 44 | 11.4% | 11.6% | 12.9% |
| Age 45 to 54 | 12.6% | 8.2% | 12.6% |
| Age 55 to 59 | 5.4% | 6.3% | 6.7% |
| Age 60 to 64 | 3.0% | 5.9% | 6.3% |
| Age 65 to 74 | 6.3% | 10.3% | 9.6% |
| Age 75 to 84 | 4.2% | 7.2% | 4.5% |
| Age 85 and over | 2.8% | 4.4% | 1.9% |
| space1 | | | |
| Race | | | |
| | Callender, IA | Leon, IA | United States |
| White | 91.4% | 97.4% | 59.4% |
| Black | 0.0% | 0.0% | 12.2% |
| Asian | 0.0% | 0.0% | 5.6% |
| Native American | 0.2% | 0.0% | 0.6% |
| Hawaiian, Pacific Islander | 0.0% | 0.0% | 0.2% |
| Other | 0.7% | 0.0% | 0.4% |
| Two or More Races | 2.6% | 1.5% | 3.2% |
| Hispanic | 5.1% | 1.2% | 18.4% |
| space2 | | | |
| Marriage & Family | | | |
| | Callender, IA | Leon, IA | United States |
| Married Population | 52.8% | 41.8% | 49.8% |
| Currently Married | 51.2% | 39.5% | 48.0% |
| Married but Separated | 1.7% | 2.3% | 1.8% |
| Single Population | 47.2% | 58.2% | 50.2% |
| Never Married | 31.0% | 30.8% | 33.8% |
| Divorced | 10.6% | 17.3% | 10.8% |
| Widowed | 5.6% | 10.1% | 5.6% |
| space5 | | | |
| Household Size | 2.60 | 2.12 | 2.60 |
| Households | 165 | 776 | 124,010,992 |
| Family Households | 100 | 356 | 80,755,759 |
| Married couple, w/children | 44.0% | 29.5% | 30.5% |
| Married couple, no children | 32.0% | 47.2% | 42.9% |
| Non Family Households | 65 | 420 | 43,255,233 |
| Single householder, w/children | 15.0% | 19.4% | 15.8% |
| Single householder, no children | 9.0% | 3.9% | 10.8% |