Census tract · Cobb County
Census Tract 311.21, Cobb County, Georgia
Census Tract 311.21, GEOID 13067031121, in Cobb County, Georgia, mostly within Smyrna (78% of its census blocks). 2,477 residents in the ACS 2020-2024 5-year estimates (±389); the 2020 Census counted 2,788.
Residents, 2020-2024
2,477
±389 (90% margin)
2020 Census count: 2,788
Median household income
$72,730
±$15,492 (90% margin)
Cobb County: $102,738
Median home value
$271,400
±$18,915 (90% margin)
Cobb County: $407,200
Median gross rent
$1,612
±$207 (90% margin)
Cobb County: $1,730
Where is Census Tract 311.21?
Census Tract 311.21 is one of 186 census tracts in Cobb County, Georgia. It covers 0.39 square miles of land, 7,186 residents per square mile in 2020. Its GEOID, 13067031121, names it uniquely (how tract numbers and GEOIDs work).
| Place | Share of the tract |
|---|---|
| Smyrna | 78% |
4 census tracts border Census Tract 311.21: Tract 310.01 ($66,423), Tract 311.13 ($66,250), Tract 311.14 ($68,739) and Tract 311.22 ($108,167). The figure in brackets is each tract's median household income.
Whether a tract counts as low- or moderate-income for bank lending (the Community Reinvestment Act) is set by the FFIEC against its metro area's family income: look it up in the FFIEC census geocoder.
Source: 2024 Gazetteer and 2020 block assignment files, U.S. Census Bureau · Census reference files
How many people live in Census Tract 311.21?
The 2020-2024 American Community Survey puts Census Tract 311.21's population at 2,477 (±389) in 1,537 households; the 2020 Census counted 2,788 residents and 1,717 housing units.
| Measure | Tract 311.21 | Smyrna |
|---|---|---|
| Total population | 2,477±389 | 56,633 |
| Households | 1,537±244 | 24,809 |
| Average household size | 1.61±0.16 | 2.27 |
| Housing units | 1,688±204 | 27,040 |
Source: American Community Survey 2020-2024 5-year estimates, U.S. Census Bureau (released January 2026); 2020 Census P.L. 94-171 · Check it at data.census.gov
Who lives in Census Tract 311.21?
The median resident of Census Tract 311.21 is 38.2 years old; 12.4% are under 18 and 19.6% are 65 or older. The largest group is non-Hispanic Black residents at 52.9%, then non-Hispanic white residents at 21.2%. 19.3% of residents were born outside the United States.
| Measure | Tract 311.21 | Smyrna |
|---|---|---|
| Median age | 38.2±6.0 | 35.7 |
| Under 18 years | 12.4%±6.8 pts | 21.6% |
| 65 years and over | 19.6%±7.3 pts | 10.4% |
| Hispanic or Latino (any race) | 12.2%±6.2 pts | 12.9% |
| White alone, not Hispanic | 21.2%±5.6 pts | 42.0% |
| Black or African American alone, not Hispanic | 52.9%±11.3 pts | 31.6% |
| Asian alone, not Hispanic | 7.8%±5.8 pts | 7.8% |
| American Indian and Alaska Native alone, not Hispanic | 0.0%±1.9 pts | 0.1% |
| Native Hawaiian and Other Pacific Islander alone, not Hispanic | 0.0%±1.9 pts | 0.2% |
| Two or more races, not Hispanic | 5.9%±3.9 pts | 5.1% |
| Some other race alone, not Hispanic | 0.0%±1.9 pts | 0.4% |
| Born outside the United States | 19.3%±9.0 pts | 15.0% |
| Speak a language other than English at home (age 5+) | 18.7%±8.5 pts | 21.3% |
| Civilian veterans (age 18+) | 5.0%±4.0 pts | 4.3% |
| With a disability | 9.4%±4.0 pts | 8.0% |
| No health insurance coverage | 7.5%±4.4 pts | 10.9% |
| High school graduate or higher (age 25+) | 98.2%±1.6 pts | 95.1% |
| Bachelor's degree or higher (age 25+) | 51.4%±9.8 pts | 59.4% |
| Graduate or professional degree (age 25+) | 18.2%±7.7 pts | 24.1% |
| Lived in the same house a year earlier | 68.0%±10.4 pts | 82.9% |
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 Census Tract 311.21 earn?
Half of the 1,537 households in Census Tract 311.21 earn less than $72,730 a year (±$15,492), against $102,738 across Cobb County: 153rd highest of the county's 186 tracts with a reliable estimate. 6.6% of residents live below the poverty line.
| Measure | Tract 311.21 | Smyrna |
|---|---|---|
| Median household income | $72,730±$15,492 | $100,061 |
| Mean household income | $78,330±$9,862 | $146,792 |
| Per capita income | $48,401±$6,111 | $64,689 |
| People below the poverty line | 6.6%±4.2 pts | 10.6% |
| Children under 18 below the poverty line | 3.2%±6.0 pts | 15.9% |
| Households receiving SNAP | 5.9%±5.1 pts | 5.6% |
| Households with a computer | 100.0%±3.0 pts | 99.0% |
| Households with a broadband subscription | 95.6%±4.4 pts | 97.2% |
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 Census Tract 311.21?
Owners occupy 38.4% of Census Tract 311.21's occupied homes and renters 61.6%. The median owner-occupied home is valued at $271,400 by its owner (±$18,915). The median renter pays $1,612 a month including utilities, and 38.1% of renters pay 35% or more of their income on rent.
| Measure | Tract 311.21 | Smyrna |
|---|---|---|
| Median home value (owner-occupied) | $271,400±$18,915 | $449,500 |
| Median gross rent | $1,612±$207 | $1,739 |
| Renters paying 35% or more of income on rent | 38.1%±13.8 pts | 41.4% |
| Median monthly owner costs, with a mortgage | $1,517±$229 | $2,438 |
| Owner-occupied homes | 38.4%±11.5 pts | 59.4% |
| Renter-occupied homes | 61.6%±11.5 pts | 40.6% |
| Housing units | 1,688±204 | 27,040 |
| Single-family detached homes | 12.2%±6.1 pts | 45.8% |
| Mobile homes | 0.5%±0.9 pts | 0.6% |
| Built 2020 or later | 3.7%±3.9 pts | 2.4% |
| Built 2010 to 2019 | 13.3%±6.2 pts | 13.0% |
| Built 1939 or earlier | 2.1%±3.2 pts | 0.9% |
| Households with no vehicle | 3.0%±3.3 pts | 4.0% |
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 Census Tract 311.21 get to work?
72.8% of Census Tract 311.21's workers drive alone and 20.4% work from home. The average trip to work takes 27.3 minutes.
| Measure | Tract 311.21 | Smyrna |
|---|---|---|
| In the labor force (age 16+) | 78.6%±5.6 pts | 75.8% |
| Unemployment rate | 3.6%±3.5 pts | 3.7% |
| Drove alone to work | 72.8%±10.1 pts | 60.4% |
| Carpooled | 2.9%±2.7 pts | 6.5% |
| Public transportation | 0.0%±3.0 pts | 0.3% |
| Walked | 0.0%±3.0 pts | 1.4% |
| Worked from home | 20.4%±7.4 pts | 29.6% |
| Mean travel time to work | 27.3 min±3.6 | 29.8 min |
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
How does Census Tract 311.21 compare with the other tracts in Cobb County?
Among Cobb County's tracts with a reliable estimate, Census Tract 311.21 ranks as shown below (1 = highest).
| Measure | In Cobb County | In Smyrna |
|---|---|---|
| Population | 170th of 186 | 19th of 20 |
| Residents per square mile | 3rd of 186 | 1st of 20 |
| Median household income | 153rd of 186 | 15th of 20 |
| Per capita income | 102nd of 186 | 14th of 20 |
| Median home value | 165th of 183 | 18th of 20 |
| Median gross rent | 121st of 160 | 13th of 18 |
| Poverty rate | 51st of 62 | 6th of 9 |
| Bachelor's degree or higher | 89th of 185 | 15th of 20 |
| Median age | 104th of 186 | 6th of 20 |
| Owner-occupied share | 161st of 184 | 14th of 20 |
The tracts next to it on Cobb County's income ladder
| Tract | Rank | Median household income |
|---|---|---|
| Tract 307 | 150th | $73,542±$20,912 · within the margin of this tract |
| Tract 304.05 | 151st | $73,477±$15,119 · within the margin of this tract |
| Tract 313.17 | 152nd | $72,984±$22,717 · within the margin of this tract |
| Tract 311.21 | 153rd | $72,730±$15,492 |
| Tract 314.09 | 154th | $71,970±$4,144 · within the margin of this tract |
| Tract 309.11 | 155th | $71,815±$19,757 · within the margin of this tract |
| Tract 305.11 | 156th | $71,777±$13,076 · within the margin of this tract |
"Within the margin": the two incomes differ by less than their combined 90% margins, so the survey cannot say which is higher and the ranks between them are not firm.
Source: PlainCities ranks computed from the American Community Survey 2020-2024 5-year estimates, U.S. Census Bureau (released January 2026) · How ranks are computed
How reliable are the figures for Census Tract 311.21?
1 of the 18 figures for Census Tract 311.21 on this page carries a coefficient of variation over 40% and is marked with a ring: they come from a small sample, so read them as rough.
A census tract's figures rest on a few hundred sampled households over five years, so its margins are wider than a city's. Two tracts differ only when the gap between them is larger than their combined 90% margin (the square root of the sum of the two squared margins). 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 · Check it at data.census.gov
How these figures are made: methodology and release checks · reading a margin of error · every state · corrections