County Map with Cities
By Marko Visic · Updated Oct 7, 2026
Interactive map of every US county with all cities and towns inside it labeled by population. Search any of 3,144 counties, see demographics, and download the complete city list as CSV. Free, unlimited, no sign-up.
County Map with Cities
Search a county or click the map to see all cities and towns inside it
Browse counties by state
It shows the boundary of any US county along with the postal cities (aggregated from ZIP codes) inside it, sized and labeled by population. Includes a full demographic profile and an exportable city list.
All 3,144 US county-equivalents — including Louisiana parishes, Alaska boroughs, Virginia independent cities, and the District of Columbia. Cities are USPS postal-city names aggregated from ZIP codes via SimpleMaps (about 27,722), with populations that sum the ZIP populations.
Sales territory mapping, school district planning, journalism and research, real estate market analysis, political organizing, candidate sourcing, and any time you need a clean visual of "what cities are in this county".
Yes — no sign-up and no API key. The map runs in your browser and each county's city list is fetched on demand from a free, cached endpoint.
What this map shows
County map with cities is the answer to the surprisingly hard question: "what cities are in this county?" County websites usually list a few; Wikipedia buries the rest in prose; Google Maps shows you a zoomable map with no county boundaries. This tool fills that gap with an interactive map of any US county, with the postal cities aggregated from ZIP codes inside it drawn as a labeled marker sized by population.
For each county, the tool shows: the official boundary polygon (from US Census TIGER/Line), the postal cities aggregated from ZIP codes inside it sized by population, a demographic card with population/area/density/income/age/education/poverty, the county seat, and a sortable table of every city with its share of the county's total population. The CSV export is ready to drop into a spreadsheet, CRM, or BI tool.
All 3,144 US county-equivalents are included — counties, Louisiana parishes, Alaska boroughs, Virginia independent cities, and DC. The county boundaries load once into your browser and each county's city list is fetched on demand from a fast cached endpoint, so switching between counties feels instant. No sign-up and no API key.
Counties vs cities — the relationship
US counties and cities have a messy relationship that often confuses people. The short version:
- Counties contain cities, mostly. A typical county has 5–50 incorporated cities inside its boundaries plus a handful of unincorporated CDPs.
- Cities can span counties. Some cities (Atlanta GA, Kansas City MO, NYC) cross county lines. The dataset here assigns each city to its primary county — the one with most of its population.
- NYC is five counties. Each borough is its own county-equivalent: Manhattan = New York County, Brooklyn = Kings County, Queens = Queens County, Bronx = Bronx County, Staten Island = Richmond County.
- Some cities are counties. Independent cities (mostly in Virginia, plus Baltimore MD, St. Louis MO, Carson City NV) are not part of any county — they are their own county-equivalent. They appear in this tool as their own "county".
- Not every place is a city. The Census tracks ~19,500 incorporated places + ~10,000 Census-designated places (CDPs). This tool's list is built from USPS postal-city names instead, so many unincorporated places (like Silver Spring MD) still appear whenever they have their own ZIP codes.
How to use this tool
The largest US counties — useful starting points
These are the most-populated US counties — search any of them above to see the full city list. Population is approximate and refreshes with each Census ACS release; the postal-place count is the number of distinct postal cities the dataset places in each county.
| County | State | Population | Postal places | Largest city |
|---|---|---|---|---|
| Los Angeles | CA | ~9.8M | 133 | Los Angeles |
| Cook | IL | ~5.2M | 97 | Chicago |
| Harris | TX | ~4.7M | 26 | Houston |
| Maricopa | AZ | ~4.5M | 39 | Phoenix |
| San Diego | CA | ~3.3M | 52 | San Diego |
| Orange | CA | ~3.2M | 47 | Anaheim |
| Miami-Dade | FL | ~2.7M | 9 | Miami |
| Kings (Brooklyn) | NY | ~2.6M | 1 | Brooklyn |
| Dallas | TX | ~2.6M | 20 | Dallas |
| Queens | NY | ~2.3M | 41 | Queens |
| Riverside | CA | ~2.4M | 43 | Riverside |
| Travis | TX | ~1.3M | 9 | Austin |
Who needs a county map with cities
1. Sales territory and route planning
Sales managers carve up the country into county-based territories and need a city list per county to brief reps, plan visits, and load CRMs. The CSV export drops straight into Salesforce, HubSpot, or routing tools like Routific.
2. Real estate and market analysis
Brokers, investors, and developers analyze counties to compare submarkets. The city map plus median income, density, and home value gives fast context — which cities inside this county are upscale, which are working-class, and where the growth is happening.
3. Political organizing and journalism
Campaign organizers and reporters use county maps to plan ground game and find sources. A county view of cities helps ID where votes are concentrated and which local officials to talk to.
4. School district and education planning
In states where districts are organized at the county level (Florida, Maryland, Nevada), this tool gives the entire student-feeder geography in one view. Educators and charter operators use it to plan outreach.
5. Public health and emergency planning
County health departments coordinate response across all cities in their jurisdiction. A clean visual of which cities to alert, where vaccination clinics should go, or which towns to evacuate is operationally useful.
6. Retail and franchise siting
Retailers and franchisors evaluating counties for expansion need to see which cities are inside the boundary, how big each is, and how clustered the population is. The size-by-population markers give an instant heat map.
7. Genealogy and family history
Family historians track ancestors by county because vital records, deeds, and census records are filed at the county level. A map of all the cities and towns in a county helps locate where ancestors lived and which courthouse holds their records.
8. Education and reference
Teachers, students, and trivia enthusiasts use the tool to learn US geography. Seeing all the cities in your home county labeled on a map is a fast way to internalize the relationships between places you've heard of.
Methodology
County boundaries
County polygons come from the US Census Bureau TIGER/Line shapefiles, distributed in topojson format via the us-atlas project (10 m resolution). The full file is ~1 MB and loads once into your browser. Each county feature carries its 5-digit FIPS code as its id, which is the join key to demographics and city data.
City data
Cities are USPS postal-city names, aggregated to city level from the SimpleMaps US ZIP Codes database: each city is positioned at the geometric centroids of the Census ZIP Code Tabulation Areas (ZCTAs) assigned to it, and its population sums the populations of those ZIPs. Each city is stamped with the FIPS code of the county where most of its population lives. The full dataset has about 27,722 postal cities.
City filtering
When you pick a county, the tool filters the city dataset to countyFips === selectedFips and sorts the result by population descending. The largest cities draw on top of smaller ones, and labels are sorted so the biggest cities take label priority when there's collision.
Demographic enrichment
Once a county is matched, the tool joins to counties.json — a pre-built file with population, area, density, median income, median age, college rate, poverty rate, county seat, and counts of cities and ZIPs for every US county.
How this compares to alternatives
County mapping with cities is offered by several tools, but most are paywalled or text-only. Here's an honest side-by-side.
| Source | Free? | Visual | Bulk export | Sign-up | Notes |
|---|---|---|---|---|---|
| SimpleMapLab (this tool) | Yes | Map + sized markers + labels | CSV per county | No | Census-derived, runs in browser |
| Wikipedia county pages | Yes | Static thumbnail | No | No | City list often in prose, hard to extract |
| Census.gov QuickFacts | Yes | Tables only | Bulk download | No | Authoritative source, no city visualization |
Limitations & accuracy notes
- Cities are points, not polygons. Each city is shown as a single dot at the geometric centroid of its ZCTAs. A large city like Houston extends 25+ miles end-to-end, but on this map it's a single sized marker.
- Cities that span counties get one home. The dataset assigns each city to its primary county — the one with most of its population. A small fraction of a city's population may technically live in a neighboring county and not be counted in this view.
- Population is annual, not real-time. Census ACS estimates lag by 1–3 years. Use this tool for planning and analysis, not for legal or compliance reporting.
- Boundary precision is ~10 m. County polygons are simplified to ~10 m for fast browser rendering. Coastline and small island detail may be reduced compared to the original Census shapefiles.
- Some counties have empty city counts. Very small or very rural counties may have only one or two populated places — sometimes zero with the minimum population filter on. Reset to "All" if a county looks empty.
- Not all county seats are populated in the data. The seat field is filled where SimpleMaps has it; some less-common counties may not have a seat shown. This doesn't affect the boundary or city list.
Glossary
- County
- A primary subdivision of a US state, used for local government, courts, public health, and tax assessment. The US has 3,144 county-equivalents in total.
- County seat
- The town or city that hosts the county government and main courthouse. Highlighted with a "Seat" badge in the city table whenever the data is available.
- Census-designated place (CDP)
- A populated area without its own government that the Census Bureau tracks for statistical purposes (e.g. Silver Spring MD, The Villages FL). These appear in the city list alongside incorporated cities.
- Incorporated city
- A city with its own legal government and charter — Los Angeles, Chicago, Atlanta. Treated as a city in the list.
- FIPS code
- A 5-digit Federal Information Processing Standard identifier for a county. First 2 digits = state, last 3 = county within state. The universal key for joining federal county data.
- Geometric centroid
- The geometric center of a ZIP Code Tabulation Area (ZCTA) polygon — the coordinate SimpleMaps assigns to each ZIP. Each city marker on the map sits at the geometric centroid of the ZCTAs assigned to that city, not a population-weighted point.
- Density
- People per square mile. For a county, computed as total population ÷ land area. Manhattan-area counties top 70,000/mi² while frontier counties drop below 1/mi².
- Independent city
- A city that is not part of any county, treated as a county-equivalent in federal data. Most are in Virginia (39); also Baltimore MD, St. Louis MO, Carson City NV.
Related tools and resources
For the inverse question — "what county is this address in?" — use Address to County Lookup. To find every city inside a circular area instead of a county boundary, use Find Cities in Radius. For aggregate population and demographics inside a radius, use Population Within Radius. Browsing by state? Each state has a county directory:
Frequently asked questions
County boundary polygons from the US Census Bureau TIGER/Line shapefiles, distributed via us-atlas. City names, coordinates, and population from the SimpleMaps US ZIP Codes Database, aggregated to city level from the geometric centroids of the Census ZIP Code Tabulation Areas assigned to each city. Demographics from the US Census American Community Survey via SimpleMaps. Map rendering via MapLibre GL JS with OpenFreeMap tiles. County selection via inline ray-casting point-in-polygon (no library dependency).