Population Within Radius

Calculate total US population, density, and demographics inside any circular area. Median income, age, education, housing, top counties, and top cities. Free, unlimited, no sign-up.

Population Within Radius

Calculate total population and demographics for any circular area in the US

🇺🇸United States only

Center Location

Unit

Radius

Quick:

Loading population data (40K+ ZIPs)...

Enter an address, use GPS, or click on the map to calculate the population and demographics inside your radius.

Definition

How does this calculate population?

It sums the population of every US ZIP Code Tabulation Area (ZCTA) whose centroid falls inside your radius, using US Census American Community Survey data. Demographics are population-weighted averages across the same ZIPs.

Coverage

How accurate is the data?

Population, income, age, housing, and education are from the latest annual US Census ACS release via SimpleMaps (2020s vintage, 1–2 year lag). Distance uses the Haversine great-circle formula. The dataset covers 41,551 US ZIPs and ~330 million residents.

Use case

When should I use this tool?

Use it for site selection, trade-area analysis, retail catchment estimation, demographic targeting, healthcare planning, real estate due diligence, and feasibility studies. Anywhere you need a population number plus context for a circular area.

Cost

Is the tool free?

Yes — no sign-up, no API key, no usage limits. The full database loads once into your browser and every recalculation is instant. Equivalent commercial tools (Esri Business Analyst, Claritas, etc.) start at $1,000+/year.

On this page

What this tool measures
How to use the tool
Common search examples
Typical population by region
Use cases & worked examples
Methodology
How this compares to alternatives
Limitations & accuracy notes
Glossary
Frequently asked questions

What this tool measures

Population within radius answers the question: "how many people live within X miles of this point?" — and goes beyond a single number to give you the full demographic picture of that area. Total population, density, median income, median age, home values, rent, education levels, poverty rate, commute time, plus the top counties and cities inside the circle.

Under the hood, the tool sums every US ZIP Code Tabulation Area (ZCTA) whose centroid falls inside your radius and computes population-weighted averages of the underlying US Census American Community Survey data. The result is similar to what you'd get from Esri Business Analyst or Claritas — but free, instant, and with no sign-up.

This is the kind of analysis that powers retail site selection, healthcare catchment planning, real estate due diligence, marketing trade-area sizing, and feasibility studies. Anywhere you need to size and characterize a circular geography around a point.

How to use this tool

Set your center point

Click anywhere on the map, search an address or ZIP, or use "Detect My Location" to start from your GPS position. The marker is draggable — slide it to fine-tune the position without losing your radius.

Adjust the radius

Drag the small white handle on the east edge of the circle to expand or shrink, use the slider, type a distance, or click a preset (5/10/25/50/100 mi). Toggle miles/kilometers anytime — population, demographics, and breakdowns recalculate instantly.

Read the results

See total population, density, housing units, and population-weighted demographics — median income, age, home value, rent, education, poverty rate, commute time. Top 10 counties and cities are ranked by share of total population. Export the underlying ZIPs to CSV.

Common search examples

Real numbers from this tool, useful as a sanity check before you run your own search. Income figures are population-weighted median household income.

Center	State	Radius	Population	Density	Median Income
New York	NY	10 mi	~6.3M	20K/mi²	$84K
Los Angeles	CA	10 mi	~3.5M	11K/mi²	$72K
Chicago	IL	10 mi	~2.7M	8.6K/mi²	$65K
Houston	TX	15 mi	~3.2M	4.5K/mi²	$68K
Phoenix	AZ	15 mi	~3.1M	4.4K/mi²	$70K
Atlanta	GA	15 mi	~1.9M	2.7K/mi²	$74K
Dallas	TX	15 mi	~3.0M	4.2K/mi²	$72K
Boston	MA	10 mi	~2.4M	7.6K/mi²	$95K
Seattle	WA	10 mi	~1.4M	4.5K/mi²	$98K
Denver	CO	10 mi	~1.3M	4.1K/mi²	$84K

Typical population by region type

Population scales dramatically with urbanization. A 25-mile radius around midtown Manhattan contains ~16 million people. The same radius in western Nebraska contains ~25,000 — a 600× difference.

Region type	Example	5 mi	25 mi	50 mi
Dense urban	Manhattan, NYC	~2.5M	~16M	~22M
Major metro	Chicago, Atlanta, Dallas	~700K	~5M	~9M
Mid-size city	Boise, Tulsa, Knoxville	~150K	~700K	~1.2M
Small town	Burlington VT, Bend OR	~50K	~150K	~250K
Rural / frontier	Western Nebraska, NE Nevada	~3K	~25K	~70K

Who uses population-within-radius

1. Retail site selection

Retailers picking new store locations need to know how many people live within a realistic drive of each candidate site, plus their income and household characteristics. A typical big-box retailer wants 100K+ residents within 5 miles and median household income above a target threshold.

EXAMPLE

Center: candidate strip mall in Plano, TX. Radius: 5 mi. Result: ~285K residents, median income ~$98K, college rate 52%, density 3,600/mi² — strong match for an upscale fitness brand.

2. Healthcare catchment planning

Hospitals, urgent-care chains, and specialist clinics use radius population to estimate patient volume and plan facility expansions. CMS programs, certificate of need filings, and insurance contracts often require ZIP-coded reporting of primary service areas.

EXAMPLE

Center: existing hospital in Greenville, SC. Radius: 25 mi. Result: ~620K residents, median age 39, poverty rate 13% — useful for projecting Medicare and Medicaid mix.

3. Real estate due diligence

Investors evaluating apartment complexes, retail centers, or office parks pull radius population and demographics as part of standard underwriting. The home value, rent, and home ownership figures provide quick context on the local housing market.

4. Marketing trade-area sizing

Marketers estimate addressable audience for billboards, local TV ads, and geo-targeted digital campaigns by pulling radius population around each location. The county breakdown maps onto designated marketing areas (DMAs) for media buys.

5. Feasibility studies and grant applications

Nonprofits and economic development agencies need defensible population numbers for grant applications, feasibility studies, and impact reports. The CSV export provides ZIP-level documentation of how the figure was computed.

6. Franchise and dealership planning

Franchisors and OEMs allocate exclusive territories based on population thresholds. A typical car dealership needs 200K residents in a 15-mile radius to justify the investment; a fast-food franchise might need 25K in a 3-mile radius.

7. School district and education planning

Charter schools and private school chains use radius population to estimate student pipeline. Combined with median income and education metrics, it helps decide which neighborhoods can support tuition or where to focus outreach.

8. Insurance underwriting and risk modeling

Insurance carriers use population density and demographics to model exposure inside a radius (think hurricane catastrophe modeling, wildfire WUI exposure, etc.). The numbers feed reinsurance treaties and rate filings.

Methodology

Population calculation

For each search, the tool iterates through every US ZIP in the SimpleMaps dataset, computes the great-circle (Haversine) distance from your center point to the ZIP's population-weighted centroid, and includes the ZIP if that distance is ≤ your radius. Total population is the sum of populations of every included ZIP.

pop_total = Σ pop_i  for all ZIPs i where d(center, zip_i) ≤ R

d  = Haversine great-circle distance (Earth radius 3959 mi)
R  = your selected radius

Population-weighted demographics

Median income, median age, home value, college rate, and similar metrics are computed as population-weighted averages across the included ZIPs. A ZIP of 50,000 people contributes 10× more to the result than a ZIP of 5,000.

metric_avg = Σ (metric_i · pop_i) / Σ pop_i

This is the same approach Census uses internally to compute area-level statistics from sub-area data. It is more honest than a simple unweighted average, which would let a tiny ZIP with 100 residents contribute equally to a metro of millions.

Density

Population density is total population ÷ geodesic area of the radius circle (in mi²). The radius circle is rendered as a true geodesic polygon using Turf.js (80 vertices), so its area accounts for Earth's curvature.

How this compares to alternatives

Population-within-radius is a niche commercial product — most tools that do this charge for it. Here's an honest side-by-side.

Source	Free?	Visual	Demographics	Sign-up	Notes
SimpleMapLab (this tool)	Yes	Map + ZIP heat dots	8 metrics	No	ACS-derived, runs in browser, instant
US Census Bureau (data.census.gov)	Yes	None / table	Hundreds	No	Authoritative source, no radius UI
Esri Business Analyst	No	Full GIS	Hundreds	Paid	Industry standard, $1K+/year
Claritas / Nielsen	No	Reports	Hundreds	Paid	Marketing segmentation focus, $$$
PolicyMap	Limited	Map	Many	Account	Strong for housing & policy

Limitations & accuracy notes

Centroid-based inclusion is binary. A ZIP whose centroid is just outside your radius is excluded entirely, even if 49% of its population technically lives inside the circle. Errors are largest for very large rural ZIPs.
Residential population only. The number is where people sleep, not where they work. Daytime population in dense business districts can be several times higher.
ACS lag. Census ACS estimates are 1–3 years out of date. For fast-growing or fast-shrinking areas, the actual current population may differ by 5–15%.
Population-weighted averages have caveats.Median of medians is not a true median. It's a defensible approximation for ZIP-level aggregation but a true area-level median would require microdata that isn't public.
Straight-line, not drive time.A 30-mile radius circle doesn't account for mountains, water, or road networks. Use a drive-time isochrone tool for routing or service-time analysis.
Not a substitute for compliance reporting. Use Census Bureau authoritative sources (data.census.gov) for legal, regulatory, or financial filings.

Glossary

Population-weighted average: An average that gives more influence to ZIPs with larger populations. A ZIP of 50,000 people contributes 10× more to the median income figure than a ZIP of 5,000.
ACS (American Community Survey): The annual rolling US Census Bureau survey that produces the population, income, education, and housing estimates used by this tool. 1-year ACS releases come out each fall, 5-year combined releases each December.
ZCTA: ZIP Code Tabulation Area — Census polygons used to aggregate ACS data at the ZIP level. Most "ZIP code population" numbers in the US actually refer to ZCTAs.
Population density: People per square mile. Computed here as total population inside the radius ÷ the geodesic area of the radius circle.
Trade area: The geographic area from which a business draws most of its customers. Often defined as a radius around a store, with population and income used to estimate revenue potential.
Catchment area: A healthcare or service term for the geographic region served by a facility. Used in hospital network planning, school district analysis, and retail siting.
Median income: The household income such that half of households earn less and half earn more. Less skewed by very high earners than mean income, which is why Census uses it.
Daytime vs nighttime population: This tool reports residential (nighttime) population — where people sleep. Daytime population (where they work) can be 2–10× larger in dense business districts. Use commercial tools for daytime estimates.

Related tools and resources

For a list of every ZIP code (rather than aggregate stats) within a radius, use Find ZIP Codes in Radius. For a list of cities, use Find Cities in Radius. For drawing circles on a worldwide map without US data attached, use the Map Radius Tool. Browsing 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 Tennessee

Frequently asked questions

It sums the population of every US ZIP Code Tabulation Area (ZCTA) whose centroid falls inside your radius. Each ZCTA contributes its full Census ACS population if its center is inside the circle, or zero if it is outside.

From the US Census Bureau American Community Survey (ACS), accessed via the SimpleMaps US ZIP Codes database. The dataset covers 41,551 US ZIPs and is refreshed annually as new ACS releases come out.

Within ~2–5% of true population for most areas. Sources of error: (1) the centroid-based inclusion misses ZIPs that partially overlap your circle, (2) ACS data lags by 1–3 years, and (3) very large rural ZIPs may have a centroid outside the circle even when most of their land is inside.

Yes. Every metric (median income, age, home value, college rate, etc.) is computed as a population-weighted average across the ZIPs in your radius. A ZIP of 50,000 people contributes 10× more to the result than a ZIP of 5,000.

Yes — drag the small white circular handle on the east edge of the radius circle. The visual updates live, and on release the population, demographics, and breakdowns recalculate. You can also use the slider, the input box, or the preset buttons.

The ZIP tool gives you a list of ZIPs (for mailing or targeting). This tool gives you the aggregate numbers — total population, density, demographics, top counties — for the same area. Both use the same underlying dataset; they answer different questions.

No. The number is residential (nighttime) population — where people sleep, per the Census. Daytime population in dense business districts can be 2–10× higher. For daytime data, use commercial tools like Esri Business Analyst.

Yes — type up to 500 mi (≈800 km) into the radius input. A 500-mile radius from central US can return 100M+ residents. Calculation remains instant.

No. The Census ACS dataset and ZCTA boundaries are US-only. For international population analysis, look at WorldPop, GHSL, or commercial demographic services.

Each dot is the centroid of one ZIP inside your radius. The dot size scales with population, and the color goes from light green (low density) to dark green (high density), giving a quick visual sense of where people are concentrated.

Yes. The "Download CSV" button exports every ZIP in your radius with population, density, median income, median age, county, city, and distance from center.

Total population inside your radius divided by the geodesic area of the radius circle (πr², adjusted for Earth's curvature). This is the average density across the circle, not a per-ZIP average.

Median household income — the household income such that half of households earn less and half earn more. We use median (not mean) because Census reports it that way and because it's less distorted by very high earners.

PO Box ZIPs and unique ZIPs (single buildings) have no residential population, so demographic fields for them are zero or missing. They're excluded from the population-weighted averages.

Population, income, education, and housing estimates come from the most recent annual US Census ACS release, with a typical 1–2 year lag. Data refreshes when the underlying SimpleMaps dataset publishes a new vintage.

For the most common use case — total population and basic demographics in a radius — yes. For advanced GIS work (drive-time isochrones, custom polygons, dozens of demographic variables, market segmentation), Esri is still the right tool.

Yes. The underlying SimpleMaps US ZIPs Basic database is free for commercial use under their license. ACS demographics are public domain. Attribution to SimpleMapLab is appreciated where reasonable.

Search ignores state lines. ZIPs from multiple states are included, and a "States" stat card appears. The top-counties and top-cities lists span all states inside the circle.

Because the radius typically pulls in suburbs and adjacent towns, which often have different demographics than the urban core. A 25-mile radius around downtown San Francisco sweeps in higher-income suburbs that pull the median income above the city itself.

Yes — the map, drag-to-resize handle, hover popups, all stat cards, and CSV export work on phones and tablets.

Data sources & methodology

Population, density, household income, age, education, housing, race, and commute data from the SimpleMaps US ZIP Codes Database, derived from US Census Bureau ZIP Code Tabulation Areas (ZCTAs) and the American Community Survey (ACS). 41,551 ZIPs covering ~330 million US residents. Address autocomplete via Photon, reverse geocoding via Nominatim. Distances use the Haversine formula. Maps: MapLibre GL JS + OpenFreeMap tiles + Turf.js for the geodesic radius polygon.