Census-designated place · Missouri
Affton, Missouri
Affton, census-designated place, in St. Louis County, Missouri. Affton had 19,052 people in the ACS 2020-2024 5-year estimates (±1,216). GEOID 2900280.
Residents, 2020-2024
19,052
±1,216 (90% margin)
2020 Census count: 20,417
Median household income
$79,539
±$6,610 (90% margin)
Missouri: $70,702
Median home value
$212,400
±$5,885 (90% margin)
Missouri: $230,300
Median gross rent
$1,015
±$81 (90% margin)
Missouri: $1,033
Where is Affton and what county is it in?
Affton is a census-designated place: an unincorporated community the Census Bureau draws for counting, with no city government of its own, in St. Louis County, Missouri. It covers 4.6 square miles of land, 4,468 residents per square mile in 2020.
Affton is in the St. Louis, MO-IL metropolitan statistical area, which takes in 15 counties (Census Bureau delineation, July 2023).
Source: 2024 Gazetteer and 2020 place-by-county files, U.S. Census Bureau · Census reference files
How many people live in Affton, and is it growing?
The 2020-2024 American Community Survey puts Affton's population at 19,052 (±1,216). The 2020 Census counted 20,417 residents.
The Census Bureau publishes yearly population estimates for incorporated places only; Affton is a census-designated place, so its figures come from the ACS and the 2020 Census.
| Measure | Affton | St. Louis County | Change since 2015-2019 |
|---|---|---|---|
| Total population | 19,052 ±1,216 | 995,569 | no clear change |
| Households | 8,695 ±550 | 413,849 | no clear change |
| Average household size | 2.19 ±0.10 | 2.36 | no clear change |
| Housing units | 9,092 ±537 | 446,192 | no clear change |
Source: American Community Survey 2020-2024 5-year estimates, U.S. Census Bureau (released January 2026); Census PEP Vintage 2025 (SUB-EST2025, CO-EST2025); 2020 Census P.L. 94-171 · Check it at data.census.gov
Who lives in Affton?
The median resident of Affton is 42.0 years old; 17.5% are under 18 and 19.5% are 65 or older. The largest group is non-Hispanic white residents at 81.3%, then non-Hispanic residents of two or more races at 7.5%. 11.0% of residents were born outside the United States.
| Measure | Affton | St. Louis County | Change since 2015-2019 |
|---|---|---|---|
| Median age | 42.0 ±3.0 | 40.3 | no clear change |
| Under 18 years | 17.5% ±2.1 pts | 22.0% | – |
| 65 years and over | 19.5% ±2.0 pts | 19.1% | – |
| Male | 48.9% ±2.3 pts | 47.8% | – |
| Hispanic or Latino (any race) | 5.9% ±2.4 pts | 3.9% | no clear change |
| White alone, not Hispanic | 81.3% ±3.7 pts | 61.4% | −5.1 pts |
| Black or African American alone, not Hispanic | 3.0% ±1.3 pts | 24.0% | no clear change |
| Asian alone, not Hispanic | 2.1% ±1.4 pts | 4.9% | – |
| American Indian and Alaska Native alone, not Hispanic | 0.0% ±0.1 pts | 0.1% | – |
| Native Hawaiian and Other Pacific Islander alone, not Hispanic | 0.0% ±0.2 pts | 0.0% | – |
| Two or more races, not Hispanic | 7.5% ±2.5 pts | 5.3% | – |
| Some other race alone, not Hispanic | 0.2% ±0.2 pts | 0.5% | – |
| Born outside the United States | 11.0% ±2.6 pts | 8.4% | no clear change |
| Speak a language other than English at home (age 5+) | 13.2% ±3.9 pts | 10.5% | – |
| Civilian veterans (age 18+) | 7.5% ±2.0 pts | 6.0% | – |
| With a disability | 12.2% ±2.1 pts | 12.1% | – |
| No health insurance coverage | 3.1% ±1.0 pts | 5.7% | −6.0 pts |
| High school graduate or higher (age 25+) | 91.9% ±2.7 pts | 94.5% | – |
| Bachelor's degree or higher (age 25+) | 36.6% ±3.4 pts | 47.4% | +4.9 pts |
| Graduate or professional degree (age 25+) | 15.4% ±2.4 pts | 20.4% | – |
| Lived in the same house a year earlier | 91.0% ±2.5 pts | 88.2% | – |
| Moved from another state in the past year | 1.0% ±0.8 pts | 2.0% | – |
Source: American Community Survey 2020-2024 5-year estimates, U.S. Census Bureau (released January 2026) (Data Profiles DP02, DP05) · Check it at data.census.gov
What do households in Affton earn?
Half of Affton's 8,695 households earn less than $79,539 a year (±$6,610), against $82,936 in St. Louis County and $70,702 in Missouri. In 2015-2019 it was $75,034 in 2024 dollars; the margins of error cannot tell the two periods apart. 6.6% of residents live below the poverty line.
| Measure | Affton | St. Louis County | Change since 2015-2019 |
|---|---|---|---|
| Median household income | $79,539 ±$6,610 | $82,936 | no clear change |
| Mean household income | $101,652 ±$9,708 | $123,036 | – |
| Per capita income | $47,243 ±$4,940 | $51,977 | +$7,809 |
| People below the poverty line | 6.6% ±1.9 pts | 9.8% | −3.9 pts |
| Children under 18 below the poverty line | 7.8% ±5.5 pts | 13.5% | – |
| Households receiving SNAP | 5.9% ±1.9 pts | 8.0% | – |
| Households with a computer | 95.6% ±1.3 pts | 96.3% | – |
| Households with a broadband subscription | 92.0% ±2.2 pts | 93.4% | – |
Source: American Community Survey 2020-2024 5-year estimates, U.S. Census Bureau (released January 2026) (Data Profile DP03) · Check it at data.census.gov
What does housing cost in Affton?
Owners occupy 80.8% of Affton's occupied homes and renters 19.2%. The median owner-occupied home is valued at $212,400 by its owner (±$5,885). The median renter pays $1,015 a month including utilities, and 22.5% of renters pay 35% or more of their income on rent.
| Measure | Affton | St. Louis County | Change since 2015-2019 |
|---|---|---|---|
| Median home value (owner-occupied) | $212,400 ±$5,885 | $276,800 | +$28,657 |
| Median gross rent | $1,015 ±$81 | $1,209 | no clear change |
| Renters paying 35% or more of income on rent | 22.5% ±5.8 pts | 39.5% | −10.5 pts |
| Median monthly owner costs, with a mortgage | $1,498 ±$53 | $1,753 | – |
| Owner-occupied homes | 80.8% ±2.8 pts | 69.2% | +6.2 pts |
| Renter-occupied homes | 19.2% ±2.8 pts | 30.8% | – |
| Housing units | 9,092 ±537 | 446,192 | no clear change |
| Homeowner vacancy rate | 0.5% ±0.7 pts | 0.7% | – |
| Rental vacancy rate | 4.4% ±6.1 pts | 5.0% | – |
| Single-family detached homes | 83.0% ±2.3 pts | 72.0% | – |
| Mobile homes | 0.5% ±0.6 pts | 0.3% | – |
| Built 2020 or later | 0.3% ±0.4 pts | 0.7% | – |
| Built 2010 to 2019 | 2.8% ±1.2 pts | 3.5% | – |
| Built 1939 or earlier | 8.5% ±2.1 pts | 9.7% | – |
| Households with no vehicle | 3.7% ±1.5 pts | 6.6% | – |
Source: American Community Survey 2020-2024 5-year estimates, U.S. Census Bureau (released January 2026) (Data Profile DP04) · Check it at data.census.gov
How do people in Affton work and get to work?
77.1% of Affton's workers drive alone and 11.6% work from home. The average trip to work takes 23.5 minutes. The unemployment rate in 2020-2024 averaged 1.5%.
| Measure | Affton | St. Louis County | Change since 2015-2019 |
|---|---|---|---|
| In the labor force (age 16+) | 71.4% ±2.7 pts | 65.0% | – |
| Unemployment rate | 1.5% ±0.8 pts | 4.3% | −2.6 pts |
| Drove alone to work | 77.1% ±3.4 pts | 71.3% | – |
| Carpooled | 7.8% ±3.1 pts | 6.4% | – |
| Public transportation | 0.8% ±0.8 pts | 1.4% | – |
| Walked | 0.7% ±0.5 pts | 1.4% | – |
| Worked from home | 11.6% ±2.6 pts | 18.3% | +5.8 pts |
| Mean travel time to work | 23.5 min ±1.6 | 23.1 min | no clear change |
Source: American Community Survey 2020-2024 5-year estimates, U.S. Census Bureau (released January 2026) (Data Profile DP03) · Check it at data.census.gov
What census tracts are in Affton?
4 census tracts lie mostly in Affton, and 4 more reach into it (2020 census blocks). Their median household incomes run from $64,178 (Tract 2197) to $77,264 (Tract 2198.01).
| Tract | Residents, 2020-2024 | Median household income |
|---|---|---|
| Tract 2200.02St. Louis County | 3,564 | $74,831 |
| Tract 2197St. Louis County | 5,167 | $64,178 |
| Tract 2198.01St. Louis County | 3,650 | $77,264 |
| Tract 2200.01St. Louis County | 4,516 | $76,548 |
| Tract 2206.01St. Louis County | 5,718 | $91,039 |
| Tract 2208.01St. Louis County | 5,491 | $90,000 |
| Tract 2207.01St. Louis County | 3,089 | $74,257 |
| Tract 2199St. Louis County | 6,088 | $81,132 |
Source: American Community Survey 2020-2024 5-year estimates, U.S. Census Bureau (released January 2026); 2020 block assignment files (tract share = share of the tract's census blocks in Affton) · Census block assignment files
How does Affton compare with other places in Missouri?
Affton ranks 86th of 416 places in Missouri with 1,000 or more residents and a reliable estimate, by median household income.
| Measure | Rank | Of |
|---|---|---|
| Population (ACS 2020-2024) | 41st | 420 |
| Residents per square mile | 21st | 420 |
| Median household income | 86th | 416 |
| Per capita income | 48th | 420 |
| Median home value | 115th | 416 |
| Median gross rent | 119th | 398 |
| Poverty rate | 320th | 373 |
| Bachelor's degree or higher | 72nd | 404 |
| Median age | 99th | 420 |
| Owner-occupied share | 72nd | 418 |
| Work from home | 124th | 270 |
| Travel time to work | 179th | 420 |
Affton's figures with every place in Missouri (CSV)
Every place in Missouri, sortable · Compare Affton with other places
Source: PlainCities ranks computed from the American Community Survey 2020-2024 5-year estimates, U.S. Census Bureau (released January 2026) and PEP Vintage 2025 · How ranks are computed
How reliable are the figures for Affton?
12 of the 57 figures for Affton on this page carry a coefficient of variation over 40% and are marked with a ring: they come from a small sample, so read them as rough.
The American Community Survey samples about one household in eight over five years, so every figure is an estimate with a 90% margin of error (shown under each value). A ring marks an estimate whose coefficient of variation is over 40%. A change is called only when the gap between the two periods is larger than their combined 90% margin (the square root of the sum of the two squared margins), the Census Bureau's test. How to read a margin of error.
Source: American Community Survey 2020-2024 5-year estimates, U.S. Census Bureau (released January 2026): margins of error as published · ACS technical documentation
How these figures are made: methodology and release checks · reading a margin of error · every state · corrections
Not on this page: crime, weather and schools for Affton are other agencies' records. Crime: the FBI's Crime Data Explorer · climate: NOAA's U.S. Climate Normals · schools: the National Center for Education Statistics' school search.