Historical population
| Census | Pop. | Note | %± |
| 2010 | 1,262 | | — |
|---|
| 2020 | 1,282 | | 1.6% |
|---|
Callender first appeared as a census designated place in the 2010 U.S. census.[19]
As of the 2020 census, Callender had a population of 1,282. The population density was 560.8 inhabitants per square mile (216.5/km2). The median age was 46.1 years. 19.9% of residents were under the age of 18 and 23.2% were 65 years of age or older. For every 100 females, there were 104.5 males, and for every 100 females age 18 and over, there were 96.4 males age 18 and over.[20][21][22]
The census reported that 1,266 people (98.8% of the population) lived in households, 16 (1.2%) lived in non-institutionalized group quarters, and no one was institutionalized. 93.4% of residents lived in urban areas, while 6.6% lived in rural areas.[20][21]
There were 449 households, out of which 127 (28.3%) had children under the age of 18 living in them, 244 (54.3%) were married-couple households, 39 (8.7%) were cohabiting couple households, 96 (21.4%) had a female householder with no spouse or partner present, and 70 (15.6%) had a male householder with no spouse or partner present. 93 households (20.7%) were one-person households, and 47 had someone living alone who was 65 years of age or older. The average household size was 2.82. There were 317 families (70.6% of all households).[20][24]
The age distribution was 255 people (19.9%) under the age of 18, 97 people (7.6%) aged 18 to 24, 272 people (21.2%) aged 25 to 44, 360 people (28.1%) aged 45 to 64, and 298 people (23.2%) who were 65 years of age or older.[20]
There were 490 housing units at an average density of 214.3 units per square mile (82.7 units/km2), of which 449 (91.6%) were occupied and 41 (8.4%) were vacant. Of the occupied units, 291 (64.8%) were owner-occupied and 158 (35.2%) were occupied by renters. The homeowner vacancy rate was 0.3% and the rental vacancy rate was 0.0%.[20][23]