DeKalb County GIS Maps
DeKalb County, Illinois, has 100,420 residents and covers 631.3 square miles. The population declined 4.5% between the 2010 and 2020 census. More residents left than arrived over that decade. The FIPS code for DeKalb County is 17037.
DeKalb is the county's largest population center. DeKalb County also includes 13 zip codes, 12 public school districts and 37 municipalities. Those boundaries help explain why population, schools, and housing can look different from one part of the county to another. The map below shows how those county lines, zip codes, and school districts fit together, and the sections that follow use that same geography to show population, demographics, school enrollment and housing patterns in more detail.
Maps, GIS layers and sample data. Paid packages add full layers, analytics and database files.
DeKalb County Trends
- Population
- 100,420▾
- Median Home Value
- $231,900▴
- K-12 Enrollment
- 21,249▴
County analytics dashboards with historical trends & projections included in package downloads.
Free starter access previews county maps, lightweight GIS, and sample data. Paid packages unlock full GIS layers, analytics, and database files.
DeKalb County Maps
The maps below show a few of the county map styles included in our downloads. County packages include map exports in JPEG, PNG, SVG, PDF and GeoTIFF formats plus more than 20 GIS layers for mapping, research and analysis. Available layers include zip codes, area codes, subdivisions, school districts, political boundaries, roads, water features, points of interest and more.
County packages also include historical county demographics, business intelligence, analytical dashboards, AI-ready prompts, markdown files and related reference data. Everything is organized to save hours of manual work collecting current data, cleaning it and joining it together. That makes it easier to move faster on analytics, due diligence, business planning and location research. Paid packages are built for commercial use, but some package contents include source-specific attribution or notice guidance. Review Licensing & Data Source Notices.
DeKalb County Population
DeKalb County had 100,420 residents in 2020. That was 4.5% lower than in 2010. DeKalb County added 11,451 people between 2000 and 2020, which points to steady long-term growth. The county is fairly spread out, with about 159 people per square mile. Some of the county's most populated postal areas include Dekalb, Sycamore and Sandwich.
Population Trend in DeKalb County IL
DeKalb County Population per 2000, 2010 and 2020 census counts with a baseline 2030 projection.
DeKalb County Zip Codes
DeKalb County has 13 zip codes. Some of the county's most populated zip codes include Dekalb (60115), Sycamore (60178) and Sandwich (60548). Dekalb is the largest zip by population, with about 42,103 residents or 42% of the county total. Together, the three largest zips account for about 76% of all county residents based on 2020 population estimates.
Most Populated Zip Codes in DeKalb County IL
| ZIP | Area | Population | Trend |
|---|---|---|---|
| 60115 | Dekalb | 42,103 | ▾ -9% |
| 60178 | Sycamore | 22,386 | ▴ 2.5% |
| 60548 | Sandwich | 12,019 | ▾ -1.6% |
| 60135 | Genoa | 7,292 | ▴ 0.6% |
| 60112 | Cortland | 4,560 | — 0% |
| Download all zip code data | |||
DeKalb County Zip Code populations and trends per most recent census data.
DeKalb County Demographics
DeKalb County has a median age of 32.6, which makes the county a little younger than Illinois overall. About 21.8% of residents are under 18, while 13.6% are 65 or older. That gives the county a fairly even mix of younger families and older adults. The largest age group is 25 to 44 at about 30.2% of the population, which points to a solid working-age base. About 32.7% of adults have a bachelor's degree or higher, above the statewide figure of 37.2%. The county is majority White by population, with Hispanic, Asian, Black and multiracial residents making up a meaningful share of the local mix.
Key Demographics for DeKalb County IL
Median Age
32.6
Under 18
21.8%
Age 65+
13.6%
Bachelor's+
32.7%
DeKalb County School Districts
DeKalb County is served by 12 public school districts with 21,249 students enrolled in 2024. The largest districts on the county map are DeKalb Community Unit 428, Kaneland Community Unit 302 and Sycamore Community Unit 427. Those three districts account for about 68% of public school enrollment in the map area. Total enrollment has stayed fairly steady in recent years, based on district totals from 2017 to 2024.
Largest School Districts by Enrollment in DeKalb County IL
| District | Enrollment | Share | Trend |
|---|---|---|---|
| DeKalb Community Unit School District 428 | 6,771 | 31.9% | ▴ 0.8% |
| Kaneland Community Unit School District 302 | 3,908 | 18.4% | ▾ -0.8% |
| Sycamore Community Unit School District 427 | 3,720 | 17.5% | ▴ 1.5% |
| Sandwich Community Unit School District 430 | 1,872 | 8.8% | ▴ 1% |
| Genoa-Kingston Community Unit School District 424 | 1,503 | 7.1% | ▴ 0.6% |
| Download all school district data | |||
DeKalb County school district enrollment and trends per most recent NCES reporting data.
DeKalb County Housing & Real Estate
DeKalb County has a median home value of $231,900 and a median gross rent of $1,041. About 61% of occupied homes in the county are owner-occupied, so the local housing market leans heavily toward ownership. Home values run below the Illinois median, while rents come in below the state average. In March 2026, the median listing price was $353,450 and homes spent about 55 days on the market.
DeKalb County Housing Mix
DeKalb County housing mix: owner, renter and vacant units.
DeKalb County Housing Trends
DeKalb County median home value and rent trend (last 5 years).
Businesses in DeKalb County, IL
DeKalb County has 4,166 business listings across 652 categories. The largest categories in DeKalb County business listings are Churches & Religious Organizations (96, 2.3%), Auto Repair (69, 1.7%), and Parks & Recreation (68, 1.6%). The full DeKalb County business listings dataset includes names, categories, addresses and contact details where available. DeKalb County packages also include U.S. Census County Business Patterns data with establishment counts, employment and payroll by industry sector.
Top Business Categories in DeKalb County, IL
| Category | Businesses | Share |
|---|---|---|
| Churches & Religious Organizations | 96 | 2.3% |
| Auto Repair | 69 | 1.7% |
| Parks & Recreation | 68 | 1.6% |
| Contractors | 60 | 1.4% |
| Medical Offices | 55 | 1.3% |
| Gas Stations | 54 | 1.3% |
| Pizza Restaurants | 52 | 1.2% |
| Beauty Salons | 51 | 1.2% |
| Real Estate Agents | 51 | 1.2% |
| Hair Salons | 50 | 1.2% |
DeKalb County Business Listings
| Business | Category | City |
|---|---|---|
| Northwestern Medicine Ben Gordon Center Discovery House | Abuse And Addiction Treatment | Dekalb |
| Stevenson Towers | Accommodation | Dekalb |
| CWA Accounting | Accountant | Dekalb |
| OTJ Sporthorses | Active Life | Maple Park |
| Whole Body Health Acupuncture | Acupuncture | Sycamore |
| Mental Health DeKalb | Addiction Rehabilitation Center | DeKalb |
| Lovers Playground | Adult Entertainment | Dekalb |
| American Marketing and Publishing | Advertising Agency | Dekalb |
| Conserv FS | Agricultural Cooperatives | Malta |
| Wesemann Feeds | Agricultural Service | Genoa |
| Download DeKalb County business listings | ||
DeKalb County business listings sourced from Overture Maps. Includes locations with a high level of confidence.
DeKalb County Basemaps
DeKalb County map and data packages include a set of useful basemaps to help you get started quickly. These include a custom light grey canvas, USGS topo, imagery and other reference layers that make it easier to build clear, meaningful county maps using the included GIS layers, your own data or both. Pre-rendered map tiles for the light grey basemap are included so you can use them offline or host them on your own CDN.
Get the Full DeKalb County Data Package
This page shows a preview of what's included in the DeKalb County data package. The full package gives you a ready-to-use county data system with GIS layers, historical data, maps, database files and planning tools that save hours of manual data gathering, cleanup and joins. Everything is organized to help you skip data wrangling and start analysis faster.
- 20+ GIS layers for zip codes, school districts, roads, water, boundaries and more
- Historical county demographics, housing, income and trend data
- ZIP code population files and school district enrollment history
- Database files, markdowns, AI-ready prompts and documentation
- Map exports in PNG, JPEG, PDF, SVG and GeoTIFF formats
- Offline-ready data explorer, map and analytics tools
Paid packages support commercial use, client work, and derived outputs. Some package contents may include source-specific attribution or provider notices. See Licensing & Data Source Notices.
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Nearby Counties
Browse county data pages for the counties that border DeKalb County. These nearby pages include the same mix of county maps, demographic summaries, school district context, housing trends and package links.