Interactive US County Map

Choropleth map of all 3,143 US counties. Color by population, density, median income, age, college rate, or poverty rate. Click any county for the full demographic profile. Free, unlimited, no sign-up.

Interactive US County Map

All 3,143 US counties — pick a metric to color the map, click any county for details

🇺🇸United States only

County search

Color by:

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Top 10 counties by population

#	County	State	Population
1	Los Angeles County	California	9,807,501
2	Cook County	Illinois	5,192,497
3	Harris County	Texas	4,851,657
4	Maricopa County	Arizona	4,488,680
5	San Diego County	California	3,322,512
6	Orange County	California	3,138,331
7	Miami-Dade County	Florida	2,738,360
8	Dallas County	Texas	2,706,825
9	Kings County	New York	2,631,396
10	Riverside County	California	2,482,806

Click any county on the map for a full demographic profile, or pick a row above.

Definition

What does this map show?

A choropleth (color-coded) map of every US county, where the color of each county encodes a chosen demographic metric — population, density, median income, median age, college rate, or poverty rate. Click any county for the full profile.

Coverage

How many counties are included?

All 3,143 US county-equivalents — counties, Louisiana parishes, Alaska boroughs and census areas, Virginia independent cities, and the District of Columbia. Boundary data from US Census TIGER/Line via us-atlas.

Metrics

Which demographics can I visualize?

Six metrics: population, population density, median household income, median age, college education rate, and poverty rate. All from the US Census American Community Survey, aggregated to the county level via SimpleMaps.

Cost

Is it free?

Yes — no sign-up, no API key, no usage limits. Equivalent commercial county-level mapping in Esri ArcGIS or Tableau requires paid licenses ($1K+/year). This tool runs entirely in your browser after a one-time data load.

On this page

What this map shows
The 6 metrics explained
How to use the tool
Use cases
Methodology
How this compares to alternatives
Limitations & accuracy notes
Glossary
Frequently asked questions

What this map shows

This is a choropleth map — a thematic map where each region is colored in proportion to a statistical variable. Here, the regions are all 3,143 US county-equivalents and the variable is one of six demographic metrics you can switch between with one click.

Pick a metric from the "Color by" pills above the map and the entire country re-colors instantly. The legend in the bottom-left corner shows the value range and the color scale. Click any county to drill into its full demographic profile in the panel below the map. Without a selection, the panel shows the top 10 counties for the current metric — useful for spotting patterns and outliers.

All 3,143 counties are included: regular counties, Louisiana parishes, Alaska boroughs and census areas, Virginia independent cities, and the District of Columbia. Boundary polygons are from the US Census Bureau TIGER/Line shapefiles via us-atlas. Demographics are from the US Census American Community Survey, joined to counties by FIPS code.

The 6 metrics explained

Each metric tells a different story about US geography. Here's what they mean and why you might care about each one.

Metric	What it measures	Common use cases
Population	Total residents in each county	Sales territory sizing, market analysis, political districting
Population density	People per square mile (population ÷ area)	Urban vs rural patterns, retail siting, infrastructure planning
Median household income	Half of households earn more, half earn less	Real estate, retail targeting, charitable giving capacity
Median age	The middle age of all residents	Healthcare planning, retirement market sizing, education policy
College education rate	% of adults 25+ with a bachelor's degree or higher	Talent sourcing, knowledge-economy site selection
Poverty rate	% of residents below the federal poverty line	Grant applications, social services planning, economic research

Population and density use a logarithmic color scale because the values span 6+ orders of magnitude across US counties. The other 4 metrics use linear scales. In all cases the scale is clipped to the 2nd and 98th percentiles to keep outliers from washing out the rest of the map.

How to use this tool

Pick a metric to color the map

Use the "Color by" pills above the map to choose population, density, median income, median age, college rate, or poverty rate. The 3,143 county polygons re-color instantly. The legend in the bottom-left corner shows the color scale and the value range.

Find a county

Type a county name in the search box and pick from the dropdown, click anywhere on the map, or tap "Detect My Location" to use GPS. The selected county is outlined in black and the map zooms to fit it.

Read the demographic profile

Once a county is selected, the panel below the map shows population, area, density, median income, age, college rate, poverty rate, and counts of cities and ZIPs. Without a selection, you see the top 10 counties for the current metric.

Who uses an interactive county map

1. Journalism & data storytelling

Reporters use county-level choropleths to illustrate stories about elections, health outcomes, economic shifts, and migration patterns. The 6-metric switcher lets you compare narratives quickly — "is this a wealth story or a population story?"

EXAMPLE

Story: Why Sun Belt counties grew in 2020. Color by population — see the dark green clusters around Phoenix, Austin, Tampa, Charlotte, Nashville. Switch to median income — same metros are green. Switch to college rate — slightly different pattern, with Austin and Raleigh standing out.

2. Sales & marketing territory planning

Sales managers compare counties by population, income, and density to design territories with similar potential. The top-10 list under each metric is a quick way to identify priority counties.

3. Real estate market analysis

Investors and brokers compare median income, age, and density across counties to spot growth markets, identify retirement destinations, and benchmark performance.

4. Public health & epidemiology

Health departments and researchers use county maps to track disease, vaccine coverage, life expectancy, and access to care. Demographics like median age and poverty rate are key context for any health analysis.

5. Political organizing & campaigns

Campaigns use county maps to plan ground game and turnout strategy. The education and income metrics often correlate with voting patterns, making this a starting point for targeting.

6. Site selection & market entry

Retailers, franchisors, and service businesses compare counties by population and income to decide where to open new locations. The choropleth makes it easy to spot under-served metros.

7. Education & teaching

Teachers use the map to teach US geography, demographic patterns, and the mechanics of choropleth visualization. The 6-metric switcher is a built-in lesson on how the same geography looks different through different lenses.

8. Academic & policy research

Researchers studying county-level outcomes — poverty traps, regional inequality, political shifts — use the tool for quick exploratory analysis before downloading raw Census data for serious modeling.

Methodology

Boundary data

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.

Demographic data

Population, area, median income, median age, college rate, and poverty rate come from a pre-built counties.json file aggregated from the SimpleMaps US ZIPs Basic database, which itself sources from the US Census American Community Survey. ~250 KB total.

Color scale

Each county has a normalized value norm ∈ [0, 1] for the active metric. The fill color is computed via a MapLibre interpolate expression on the feature-state norm property. Switching metrics re-runs the normalization and updates the color expression in place — no source reload, no flicker.

Log vs linear scaling

Population and density are log-scaled because their ranges span 6+ orders of magnitude. Income, age, education, and poverty are linear. In both cases the value range is clipped to the 2nd–98th percentile of populated counties before normalizing, so a few extreme outliers (Loving County TX = 64 people; King County WA density = ~1,000/mi² for the metro vs the entire county) don't dominate the color range.

How this compares to alternatives

Interactive county maps exist in several tools and services. Here's an honest side-by-side.

Source	Free?	Visual	Bulk	Sign-up	Notes
SimpleMapLab (this tool)	Yes	Choropleth + click + legend	Visualize all 3,143 instantly	No	6 metrics, runs in browser
Census.gov / data.census.gov	Yes	Tables + basic maps	Bulk CSV download	No	Authoritative source, complex UI
Esri ArcGIS / Living Atlas	Free tier	Full GIS choropleth	Unlimited	Account	Industry standard, paid for advanced
Tableau Public	Yes	DIY choropleth	Per workbook	Account	Build your own, requires effort
Wikipedia county pages	Yes	Static thumbnails	No	No	Good text, no interactive map

Limitations & accuracy notes

ACS lag. Demographics are 1–3 years out of date. For fast-growing or fast-shrinking counties the actual current value may differ by 5–15%.
Small-county uncertainty. ACS estimates have a margin of error that grows for smaller counties. For counties under 5,000 residents, treat the income, education, and poverty figures as approximate.
Boundary precision is ~10 m. Polygons are simplified for browser rendering. Coastline detail and small islands may be reduced compared to the original Census shapefiles.
Percentile clipping hides extremes. A handful of counties fall outside the 2nd–98th percentile range and get the same color as the tail. The hover popup always shows the exact raw value, even for clipped outliers.
Six metrics only. The tool ships with 6 demographic metrics. For more (race, language, employment sectors, commute, housing), use a dedicated GIS like Esri ArcGIS or PolicyMap.
Not for compliance reporting. Use authoritative Census sources (data.census.gov) for legal, regulatory, or financial filings.

Glossary

Choropleth map: A thematic map where geographic regions are shaded or colored in proportion to a statistical variable. The most common way to visualize county-level demographic data.
County: A primary subdivision of a US state, used for local government, courts, public health, and tax assessment. The US has 3,143 county-equivalents.
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.
TIGER/Line: Topologically Integrated Geographic Encoding and Referencing — the US Census Bureau's authoritative geographic data product, source of the boundary polygons used here.
Population density: People per square mile. Computed here as total county population ÷ county land area. Manhattan-area counties top 70,000/mi²; frontier counties drop below 1/mi².
Median income: The household income such that half of households earn more and half earn less. Census reports median (not mean) because it is less distorted by very high earners.
Log scale: A nonlinear color scale that compresses large ranges. Population and density use log scales because they span 6+ orders of magnitude across US counties (Loving County TX = 64 people; LA County = 9.8M).
Percentile clipping: Trimming the color range at the 2nd and 98th percentiles so that extreme outliers don't wash out the rest of the map. The middle 96% of counties get the full color range.

Related tools and resources

For a single-county zoom view with all the cities labeled, use County Map with Cities. To find what county a specific address is in, use Address to County Lookup. For radius-based searches, see Find Cities in Radius and Population Within Radius. Browsing the US by state? Each state has a county directory:

California Texas Florida New York Pennsylvania Illinois Ohio Georgia North Carolina Michigan New Jersey Virginia Washington Arizona Massachusetts Colorado

Frequently asked questions

Pick a metric from the "Color by" pills (population, density, income, age, education, poverty). The map re-colors instantly. Click any county to see its full demographic profile in the panel below. Use the search box to find a specific county, or tap Detect My Location to find your own.

All 3,143 US county-equivalents — counties, Louisiana parishes, Alaska boroughs, Virginia independent cities, and the District of Columbia. The boundary file is the US Census Bureau TIGER/Line shapefile via us-atlas, simplified to ~10 m precision for fast browser rendering.

Boundary polygons from the US Census Bureau TIGER/Line shapefiles via us-atlas. Demographics (population, area, income, age, education, poverty) from the US Census American Community Survey, aggregated to county level via SimpleMaps.

For population and density we use a log scale, because the values span 6+ orders of magnitude (Loving County TX has 64 residents; LA County has 9.8M). For income, age, education, and poverty we use a linear scale. In all cases the color range is clipped to the 2nd–98th percentile so outliers don't wash out the map.

A thematic map where regions are shaded in proportion to a statistical variable. The classic example is an election map showing red and blue states by vote share. This tool produces choropleth maps for 6 different metrics across 3,143 counties.

Yes — three ways. Type the county name in the search box (autocomplete suggestions appear), click directly on the map at your home location, or tap "Detect My Location" to use GPS. The selected county is outlined in black and the map auto-fits it.

A 5-digit Federal Information Processing Standard identifier — the universal key for joining county data across federal datasets. The first 2 digits are the state, the last 3 are the county within that state. Example: Los Angeles County, CA = 06037.

A county is shown gray when the chosen metric has no value or is zero for that county. This is uncommon but can happen for very small counties with missing ACS data, or for some metrics that aren't reported below a certain population threshold.

The Census ACS estimates have a 1–3 year lag and a margin of error that grows for smaller counties. For population and basic demographics in larger counties, accuracy is within 1–2%. For very small counties (<5,000 residents), use specific estimates with care.

They're shown in their actual geographic position, not in the inset boxes you sometimes see. Alaska's boroughs and census areas are included, and Hawaii's 5 counties are shown in the Pacific. Pan and zoom to see them clearly.

It clearly shows the East Coast / Midwest urban corridor, the I-95 megalopolis, the Pacific coast metros, and the empty Mountain West. You can see why people talk about "two Americas" — the dense coastal/Great Lakes counties vs the sparse interior.

Higher-income counties cluster around DC, NYC, San Francisco, Boston, Seattle, Denver, and major energy regions (North Dakota oil counties, Texas Permian). The lowest-income counties are concentrated in Appalachia, the Mississippi Delta, and parts of the Southwest.

College-educated population clusters in major metros (NYC, DC, Boston, SF, Seattle, Austin) and university towns. Rural counties typically show 15–25% college rates; the highest-education counties exceed 65% (Falls Church VA, Arlington VA, Pitkin CO).

Yes. US Census TIGER boundary data is public domain. ACS demographics are public domain. SimpleMaps US ZIPs Basic data (used for the aggregation) is free for commercial use under their license. Attribution to SimpleMapLab is appreciated where reasonable.

Because outliers ruin choropleth maps. If we used the full range for population (Loving County 64 → LA County 9.8M), almost every county would look the same shade of light. Clipping to the 2nd–98th percentile lets the middle 96% of counties get the full color spectrum, which is what users actually want to see.

County Map with Cities is a single-county zoom view: pick one county, see its boundary and every city inside. This tool is the national overview: see all 3,143 counties at once, colored by a metric, with click-to-drill-down. Use this one to compare; use that one to explore a specific county.

Address to County Lookup answers a single question: "what county is this address in?" — point in, county out. This tool is for browsing and pattern-finding across all counties at once. Both share the same underlying boundary data.

Yes — once the boundary file (~1 MB) and demographics file (~250 KB) load, every metric switch and county click is instant. There's no server roundtrip, no rate limit, no sign-up.

Yes — the metric pills, search, GPS button, map interaction, and result panel all work on phones and tablets. Hover popups become taps on touch devices.

Map export is on the roadmap. For now, take a screenshot, or click into a specific county and download its profile via the related "County Map with Cities" tool which has a CSV export.

Data sources & methodology

County boundary polygons from the US Census Bureau TIGER/Line shapefiles, distributed via us-atlas. County demographics aggregated from the SimpleMaps US ZIP Codes Database via the US Census American Community Survey. Map rendering by MapLibre GL JS with OpenFreeMap tiles. Choropleth coloring via MapLibre feature-state and interpolate expressions, with log scaling for population/density and percentile clipping for outlier handling.