County · Illinois
DeKalb County, Illinois
DeKalb County, Illinois. DeKalb County had 101,835 residents in 2025 by the Census Bureau's estimate, up 1.3% since 2020, while Illinois shrank 0.8%. It holds 33 places (14 cities, villages and boroughs and 19 towns and townships) and 23 census tracts. GEOID 17037.
DeKalb County is one of the 13 counties of the Chicago-Naperville-Elgin, IL-IN metropolitan statistical area (the Census Bureau's July 2023 delineation).
Residents, July 2025 estimate
101,835
Census Bureau estimate (no margin published)
2020 Census count: 100,420 · ACS 2020-2024: 100,703
Median household income
$70,724
±$2,546 (90% margin)
Illinois: $83,390
Median home value
$243,600
±$5,310 (90% margin)
Illinois: $263,300
Median gross rent
$1,049
±$33 (90% margin)
Illinois: $1,274
How many people live in DeKalb County, and is it growing?
The 2020 Census counted 100,420 residents in DeKalb County. The Census Bureau estimates 101,835 for July 1, 2025, up 1.3% since 2020, while Illinois shrank 0.8%. The 2020-2024 American Community Survey puts the population at 100,703 over 631 square miles of land.
| Measure | DeKalb County | Illinois | Change since 2015-2019 |
|---|---|---|---|
| Total population | 100,703 | 12,694,798 | −3,663 |
| Households | 39,550±403 | 5,036,449 | +1,400 |
| Average household size | 2.42±0.02 | 2.46 | −0.20 |
| Housing units | 41,678±77 | 5,457,452 | +472 |
DeKalb County's population since 2000
From 88,969 in 2000 to 101,835 in 2025: up 14.5%. The 2000, 2010 and 2020 figures are census counts. The 2005 figure is the Census Bureau's intercensal estimate, revised to fit the 2000 and 2010 counts and drawn on 2010 boundaries; 2015 and 2025 are July 1 estimates made from the census before them.
Source: The 2000, 2010 and 2020 Census counts and the Census Bureau's population estimates (intercensal 2000-2010, Vintage 2020, Vintage 2025) · Census population estimates
Source: American Community Survey 2020-2024 5-year estimates, U.S. Census Bureau (released January 2026); PEP Vintage 2025 (CO-EST2025); 2020 Census · Check it at data.census.gov
What cities and towns are in DeKalb County?
DeKalb County holds 33 places: 14 cities, villages and boroughs (incorporated places) and 19 towns and townships (county subdivisions with their own government). The largest is DeKalb Township with 42,904 residents (2025 estimate). Places that cross a county line are listed with the share of their 2020 residents who live in this county.
| DeKalb Township | 42,677 | $47,082 |
|---|---|---|
| DeKalb | 40,290 | $46,481 |
| Sycamore | 18,577 | $84,120 |
| Sycamore Township | 14,702 | $87,400 |
| Cortland Township | 11,244 | $99,292 |
| Sandwich Township | 7,510 | $80,807 |
| Sandwich | 7,221 | $80,768 |
| Genoa Township | 5,527 | $91,034 |
| Genoa | 5,298 | $82,128 |
| Cortland | 4,398 | $73,971 |
| Kingston Township | 3,492 | $103,286 |
| Squaw Grove Township | 2,717 | $91,339 |
| Franklin Township | 2,231 | $88,431 |
| Hinckley | 2,006 | $86,823 |
| Somonauk Township | 2,006 | $100,119 |
| Clinton Township | 1,828 | $100,505 |
| Kirkland | 1,650 | $94,338 |
| Malta Township | 1,557 | $85,469 |
| Somonauk | 1,786 | $84,583 |
| Waterman | 1,433 | $100,139 |
| Shabbona Township | 1,344 | $81,032 |
| Malta | 1,143 | $80,625 |
| Kingston, DeKalb County | 1,108 | $88,295 |
| Afton TownshipGEOID 1703700386 | 901 | $107,675 |
| Mayfield Township | 872 | $113,375 |
| Shabbona | 863 | $63,750 |
| Maple Park | 1,433 | $107,045 |
| South Grove TownshipGEOID 1703770837 | 447 | $112,941 |
| Pierce TownshipGEOID 1703759676 | 440 | $109,216 |
| Paw Paw TownshipGEOID 1703758200 | 345 | $67,188 |
| Milan TownshipGEOID 1703748983 | 305 | $143,500 |
| Victor TownshipGEOID 1703777798 | 275 | $126,944 |
| Lee | 313 | $82,000 |
Source: American Community Survey 2020-2024 5-year estimates, U.S. Census Bureau (released January 2026); 2020 place-by-county parts · Check it at data.census.gov
Who lives in DeKalb County?
The median resident of DeKalb County is 32.7 years old; 21.6% are under 18 and 13.9% are 65 or older. The largest group is non-Hispanic white residents at 71.0%, then Hispanic or Latino residents (of any race) at 14.5%. 6.4% of residents were born outside the United States.
| Measure | DeKalb County | Illinois | Change since 2015-2019 |
|---|---|---|---|
| Median age | 32.7±0.4 | 39.0 | +1.6 |
| Under 18 years | 21.6% | 21.8% | – |
| 65 years and over | 13.9%±0.1 pts | 17.0% | – |
| Hispanic or Latino (any race) | 14.5% | 18.8% | +3.3 pts |
| White alone, not Hispanic | 71.0%±0.3 pts | 58.1% | −5.8 pts |
| Black or African American alone, not Hispanic | 6.8%±0.5 pts | 13.3% | −1.0 pts |
| Asian alone, not Hispanic | 2.2%±0.3 pts | 5.9% | no clear change |
| American Indian and Alaska Native alone, not Hispanic | 0.2%±0.2 pts | 0.1% | – |
| Native Hawaiian and Other Pacific Islander alone, not Hispanic | 0.0%±0.1 pts | 0.0% | – |
| Two or more races, not Hispanic | 4.8%±0.7 pts | 3.4% | – |
| Some other race alone, not Hispanic | 0.5%±0.3 pts | 0.4% | – |
| Born outside the United States | 6.4%±0.7 pts | 14.7% | no clear change |
| Speak a language other than English at home (age 5+) | 12.0%±0.8 pts | 24.0% | – |
| Civilian veterans (age 18+) | 5.2%±0.6 pts | 4.8% | – |
| With a disability | 11.1%±0.9 pts | 12.1% | – |
| No health insurance coverage | 5.1%±0.6 pts | 6.9% | no clear change |
| High school graduate or higher (age 25+) | 92.2%±0.8 pts | 90.5% | – |
| Bachelor's degree or higher (age 25+) | 33.0%±1.5 pts | 37.8% | no clear change |
| Graduate or professional degree (age 25+) | 13.3%±1.0 pts | 15.3% | – |
| Moved from another state in the past year | 1.9%±0.5 pts | 1.6% | – |
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 DeKalb County earn?
Half of DeKalb County's 39,550 households earn less than $70,724 a year (±$2,546), against $83,390 in Illinois. In 2015-2019 the median was $77,924 in 2024 dollars, so it fell by $7,200 after inflation. 14.8% of residents live below the poverty line.
| Measure | DeKalb County | Illinois | Change since 2015-2019 |
|---|---|---|---|
| Median household income | $70,724±$2,546 | $83,390 | −$7,200 |
| Mean household income | $90,834±$3,026 | $115,638 | – |
| Per capita income | $36,298±$1,053 | $46,406 | no clear change |
| People below the poverty line | 14.8%±1.7 pts | 11.8% | no clear change |
| Children under 18 below the poverty line | 17.3%±3.4 pts | 15.1% | no clear change |
| Households receiving SNAP | 14.7%±1.6 pts | 13.8% | – |
| Households with a broadband subscription | 92.7%±1.2 pts | 90.8% | – |
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 DeKalb County?
Owners occupy 61.4% of DeKalb County's occupied homes and renters 38.6%. The median owner-occupied home is valued at $243,600 by its owner (±$5,310). The median renter pays $1,049 a month including utilities, and 46.3% of renters pay 35% or more of their income on rent.
| Measure | DeKalb County | Illinois | Change since 2015-2019 |
|---|---|---|---|
| Median home value (owner-occupied) | $243,600±$5,310 | $263,300 | +$30,567 |
| Median gross rent | $1,049±$33 | $1,274 | −$96 |
| Renters paying 35% or more of income on rent | 46.3%±4.4 pts | 39.0% | no clear change |
| Median monthly owner costs, with a mortgage | $1,866±$47 | $1,987 | – |
| Owner-occupied homes | 61.4%±1.5 pts | 67.1% | +4.4 pts |
| Housing units | 41,678±77 | 5,457,452 | +472 |
| Homeowner vacancy rate | 0.2%±0.2 pts | 1.0% | – |
| Rental vacancy rate | 2.6%±1.1 pts | 5.0% | – |
| Single-family detached homes | 58.2%±1.6 pts | 58.2% | – |
| Mobile homes | 2.1%±0.5 pts | 2.3% | – |
| Built 2020 or later | 0.5%±0.2 pts | 0.7% | – |
| Built 1939 or earlier | 16.0%±1.5 pts | 20.2% | – |
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 many new homes is DeKalb County building?
Builders took permits for 264 new housing units across DeKalb County in 2025 (226 single-family), 2.6 per 1,000 residents.
Source: Building Permits Survey, annual county files 2019-2025, U.S. Census Bureau · Census Building Permits Survey
How do people in DeKalb County get to work?
74.8% of DeKalb County's workers drive alone and 9.3% work from home. The average trip to work takes 26.7 minutes. The unemployment rate in 2020-2024 averaged 6.8%.
| Measure | DeKalb County | Illinois | Change since 2015-2019 |
|---|---|---|---|
| In the labor force (age 16+) | 68.4%±1.3 pts | 65.0% | – |
| Unemployment rate | 6.8%±1.0 pts | 5.8% | no clear change |
| Drove alone to work | 74.8%±2.0 pts | 65.9% | – |
| Carpooled | 9.6%±1.5 pts | 7.8% | – |
| Public transportation | 0.8%±0.3 pts | 5.8% | – |
| Walked | 4.2%±0.9 pts | 2.8% | – |
| Worked from home | 9.3%±1.1 pts | 15.9% | +4.8 pts |
| Mean travel time to work | 26.7 min±1.1 | 27.8 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 are DeKalb County's census tracts?
DeKalb County is divided into 23 census tracts. Among those with a reliable estimate, median household income runs from $14,743 (Tract 10.02) to $135,455 (Tract 4.02).
Source: American Community Survey 2020-2024 5-year estimates, U.S. Census Bureau (released January 2026) · Check it at data.census.gov
How does DeKalb County compare with Illinois's other counties?
| Measure | Rank |
|---|---|
| Population | 20th of 102 |
| Growth 2020-2025 | 8th of 102 |
| Residents per square mile | 19th of 102 |
| Median household income | 42nd of 102 |
| Median home value | 10th of 102 |
| Median gross rent | 12th of 102 |
| Poverty rate | 26th of 102 |
| Bachelor's degree or higher | 15th of 102 |
| Median age | 100th of 102 |
Source: PlainCities ranks 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 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 DeKalb County 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.