Census tract · Boulder County
Census Tract 121.01, Boulder County, Colorado
Census Tract 121.01, GEOID 08013012101, in Boulder County, Colorado, mostly within Boulder (93% of its census blocks). 4,800 residents in the ACS 2020-2024 5-year estimates (±609); the 2020 Census counted 4,793.
Residents, 2020-2024
4,800
±609 (90% margin)
2020 Census count: 4,793
Median household income
$244,179
±$26,218 (90% margin)
Boulder County: $103,994
Median home value
$2,000,000 or more
The survey's top or bottom value; no margin is published
Boulder County: $756,300
Median gross rent
$2,146
±$262 (90% margin)
Boulder County: $1,966
Where is Census Tract 121.01?
Census Tract 121.01 is one of 78 census tracts in Boulder County, Colorado. It covers 1.15 square miles of land, 4,175 residents per square mile in 2020. Its GEOID, 08013012101, names it uniquely (how tract numbers and GEOIDs work).
| Place | Share of the tract |
|---|---|
| Boulder | 93% |
6 census tracts border Census Tract 121.01: Tract 121.04 ($155,313), Tract 121.05 ($102,112), Tract 121.06 ($132,227), Tract 122.01 ($123,250), Tract 122.04 ($51,583) and Tract 137.04 ($86,163). 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 121.01?
The 2020-2024 American Community Survey puts Census Tract 121.01's population at 4,800 (±609) in 2,217 households; the 2020 Census counted 4,793 residents and 2,124 housing units.
| Measure | Tract 121.01 | Boulder |
|---|---|---|
| Total population | 4,800 ±609 | 106,433 |
| Households | 2,217 ±327 | 44,432 |
| Average household size | 2.16 ±0.21 | 2.12 |
| Housing units | 2,357 ±352 | 47,465 |
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 121.01?
The median resident of Census Tract 121.01 is 45.2 years old; 19.5% are under 18 and 20.6% are 65 or older. The largest group is non-Hispanic white residents at 93.3%, then non-Hispanic residents of two or more races at 3.5%. 7.7% of residents were born outside the United States.
| Measure | Tract 121.01 | Boulder |
|---|---|---|
| Median age | 45.2 ±6.0 | 28.8 |
| Under 18 years | 19.5% ±3.7 pts | 11.8% |
| 65 years and over | 20.6% ±5.4 pts | 12.7% |
| Hispanic or Latino (any race) | 2.0% ±1.7 pts | 10.7% |
| White alone, not Hispanic | 93.3% ±3.3 pts | 78.0% |
| Black or African American alone, not Hispanic | 0.0% ±0.9 pts | 1.0% |
| Asian alone, not Hispanic | 0.3% ±0.5 pts | 5.4% |
| American Indian and Alaska Native alone, not Hispanic | 0.9% ±1.3 pts | 0.2% |
| Native Hawaiian and Other Pacific Islander alone, not Hispanic | 0.0% ±0.9 pts | 0.0% |
| Two or more races, not Hispanic | 3.5% ±2.5 pts | 4.4% |
| Some other race alone, not Hispanic | 0.0% ±0.9 pts | 0.3% |
| Born outside the United States | 7.7% ±4.0 pts | 10.8% |
| Speak a language other than English at home (age 5+) | 3.6% ±2.0 pts | 14.9% |
| Civilian veterans (age 18+) | 4.6% ±3.5 pts | 2.7% |
| With a disability | 5.3% ±3.2 pts | 7.6% |
| No health insurance coverage | 3.0% ±2.8 pts | 3.4% |
| High school graduate or higher (age 25+) | 99.6% ±0.6 pts | 97.3% |
| Bachelor's degree or higher (age 25+) | 88.6% ±4.0 pts | 76.8% |
| Graduate or professional degree (age 25+) | 49.3% ±8.1 pts | 40.4% |
| Lived in the same house a year earlier | 83.1% ±4.6 pts | 65.9% |
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 121.01 earn?
Half of the 2,217 households in Census Tract 121.01 earn less than $244,179 a year (±$26,218), against $103,994 across Boulder County: 1st highest of the county's 76 tracts with a reliable estimate. 9.4% of residents live below the poverty line.
| Measure | Tract 121.01 | Boulder |
|---|---|---|
| Median household income | $244,179 ±$26,218 | $87,493 |
| Mean household income | $334,311 ±$124,576 | $148,050 |
| Per capita income | $155,542 ±$68,040 | $63,074 |
| People below the poverty line | 9.4% ±5.0 pts | 21.5% |
| Children under 18 below the poverty line | 16.9% ±15.5 pts | 9.1% |
| Households receiving SNAP | 6.7% ±4.5 pts | 5.5% |
| Households with a computer | 100.0% ±1.9 pts | 99.0% |
| Households with a broadband subscription | 98.6% ±1.3 pts | 95.6% |
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 121.01?
Owners occupy 74.4% of Census Tract 121.01's occupied homes and renters 25.6%. The median owner-occupied home is valued at $2,000,000 or more by its owner (). The median renter pays $2,146 a month including utilities, and 30.3% of renters pay 35% or more of their income on rent.
| Measure | Tract 121.01 | Boulder |
|---|---|---|
| Median home value (owner-occupied) | $2,000,000 or more | $1,039,500 |
| Median gross rent | $2,146 ±$262 | $2,018 |
| Renters paying 35% or more of income on rent | 30.3% ±16.7 pts | 58.4% |
| Median monthly owner costs, with a mortgage | $4,000 or more | $3,210 |
| Owner-occupied homes | 74.4% ±6.8 pts | 47.2% |
| Renter-occupied homes | 25.6% ±6.8 pts | 52.8% |
| Housing units | 2,357 ±352 | 47,465 |
| Single-family detached homes | 74.5% ±7.1 pts | 38.7% |
| Mobile homes | 0.0% ±1.8 pts | 2.0% |
| Built 2020 or later | 2.2% ±1.9 pts | 1.4% |
| Built 2010 to 2019 | 6.6% ±3.9 pts | 8.1% |
| Built 1939 or earlier | 35.5% ±10.9 pts | 7.5% |
| Households with no vehicle | 2.3% ±2.5 pts | 9.1% |
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 121.01 get to work?
40.9% of Census Tract 121.01's workers drive alone and 40.5% work from home. The average trip to work takes 17.5 minutes.
| Measure | Tract 121.01 | Boulder |
|---|---|---|
| In the labor force (age 16+) | 63.4% ±6.6 pts | 63.7% |
| Unemployment rate | 2.9% ±2.8 pts | 6.0% |
| Drove alone to work | 40.9% ±10.9 pts | 39.1% |
| Carpooled | 4.7% ±3.5 pts | 3.2% |
| Public transportation | 3.0% ±2.5 pts | 5.1% |
| Walked | 2.7% ±2.3 pts | 9.5% |
| Worked from home | 40.5% ±10.4 pts | 34.4% |
| Mean travel time to work | 17.5 min ±4.0 | 18.1 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 121.01 compare with the other tracts in Boulder County?
Among Boulder County's tracts with a reliable estimate, Census Tract 121.01 ranks as shown below (1 = highest).
| Measure | In Boulder County | In Boulder |
|---|---|---|
| Population | 29th of 78 | 10th of 30 |
| Residents per square mile | 34th of 78 | 18th of 30 |
| Median household income | 1st of 76 | 1st of 29 |
| Per capita income | 1st of 78 | 1st of 30 |
| Median home value | 1st of 75 | 1st of 29 |
| Median gross rent | 32nd of 76 | 15th of 29 |
| Poverty rate | 30th of 57 | 20th of 26 |
| Bachelor's degree or higher | 2nd of 78 | 2nd of 30 |
| Median age | 24th of 78 | 6th of 30 |
| Owner-occupied share | 33rd of 76 | 8th of 28 |
The tracts next to it on Boulder County's income ladder
| Tract | Rank | Median household income |
|---|---|---|
| Tract 121.01 | 1st | $244,179±$26,218 |
| Tract 613 | 2nd | $242,614±$34,466 · within the margin of this tract |
| Tract 614 | 3rd | $201,288±$28,479 |
| Tract 130.04 | 4th | $201,146±$32,269 |
"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 121.01?
3 of the 18 figures for Census Tract 121.01 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.
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