How accurate is county detection by GPS?

Modern smartphones deliver 3–10m GPS accuracy. We perform an authoritative point-in-polygon lookup against US Census TIGER/Line county boundaries — the same dataset used by federal, state and local governments.

Yes — What County I Am In is 100% free, requires no signup, and works on any modern device.

Does this work outside the United States?

Yes. International addresses and coordinates are resolved via OpenStreetMap. US lookups additionally include the official county FIPS code.

Is my location stored?

No. Coordinates are sent to public mapping APIs only to resolve your county. We don't store, log, sell, or share your location.

Live • US Census Bureau + OpenStreetMap GIS

What county am I in right now?

The fastest, most accurate county finder on the web. Detect your county in under a second by GPS, ZIP code, address, or coordinates.

Instantly detect your county using your device's location. Works on mobile and desktop.

Your location stays on your device. We only send coordinates to public mapping APIs to look up your county.

Privacy-first Sub-second lookup Official GIS sources Works worldwide No signup

US counties indexed

ZIP codes supported

0M+

Million lookups served

0.97%

Boundary accuracy

Lookup tools

Four precision ways to find your county

Whichever signal you have — location, ZIP, address, or raw coordinates — we resolve it to the exact county polygon.

Current Location

One-tap GPS detection using your browser's geolocation API.

Open tool

ZIP Code Lookup

Search any of 41,000+ US ZIP codes. Returns county + FIPS.

Open tool

Address Finder

Enter a street address — US or international supported.

Open tool

Coordinate Reverse

Convert raw latitude/longitude into a county boundary.

Open tool

Why it matters

Your county controls more than you think

In the United States, the county is the foundational unit of local government. From the property records on your home to the court that hears your traffic ticket — almost every interaction with government happens at the county level.

Voting & Elections

Counties run polling places, ballot design, voter rolls, and certify local results.

Property Taxes

Assessors and treasurers at the county level set property tax rates and collect them.

Real Estate & Deeds

Recorder of Deeds offices store every land transaction in your county.

Courts & Jurisdiction

County courts handle family, probate, traffic, civil, and many criminal matters.

Emergency Services

Sheriffs, EMS dispatch, and disaster response are coordinated at the county level.

Mailing & Logistics

Shipping zones, sales tax nexus, and delivery routing often depend on county.

Schools & Zoning

Many school districts and zoning rules align with county boundaries.

Business Licensing

Permits, DBAs, and business filings often go through the county clerk.

By state

Explore counties in every US state

Detailed guides for the most-searched states. Each page lists every county, the largest city, FIPS codes, and an instant lookup tool scoped to that state.

View all 50 states

TX254 counties

Texas

Largest: Harris County

Texas has 254 counties — the most of any U.S. state. From Harris County (Houston) to Bexar (San Antonio) and Dallas County, county lines determine your courts, schools, taxes, and emergency services.

Find my county in Texas

CA58 counties

California

Largest: Los Angeles County

California's 58 counties range from massive Los Angeles County to tiny Alpine County. Your county controls property records, public health, and many local services.

Find my county in California

FL67 counties

Florida

Largest: Miami-Dade County

Florida has 67 counties. Miami-Dade, Broward, and Orange (Orlando) are among the largest. Hurricane evacuation zones, school districts, and tax rolls are all county-administered.

Find my county in Florida

OH88 counties

Ohio

Largest: Cuyahoga County

Ohio's 88 counties include Cuyahoga (Cleveland), Franklin (Columbus), and Hamilton (Cincinnati). County governments run elections, recorder offices, and county sheriffs.

Find my county in Ohio

PA67 counties

Pennsylvania

Largest: Philadelphia County

Pennsylvania has 67 counties. Philadelphia, Allegheny (Pittsburgh), and Montgomery are the most populous. Each county handles deeds, vital records, and the orphans' court.

Find my county in Pennsylvania

NY62 counties

New York

Largest: Kings County (Brooklyn)

New York has 62 counties — five of them are New York City's boroughs (Kings, Queens, New York, Bronx, Richmond). Outside NYC, county clerks manage records and courts.

Find my county in New York

IL102 counties

Illinois

Largest: Cook County

Illinois has 102 counties, dominated by Cook County (Chicago). Counties run the assessor, treasurer, recorder, and county board.

Find my county in Illinois

GA159 counties

Georgia

Largest: Fulton County

Georgia has 159 counties — second only to Texas. Fulton, DeKalb, Gwinnett, and Cobb make up metro Atlanta. Tag offices, tax commissioners, and probate courts are county-level.

Find my county in Georgia

NC100 counties

North Carolina

Largest: Mecklenburg County

North Carolina's 100 counties include Mecklenburg (Charlotte) and Wake (Raleigh). Counties run public health, social services, and the Register of Deeds.

Find my county in North Carolina

MI83 counties

Michigan

Largest: Wayne County

Michigan has 83 counties. Wayne (Detroit), Oakland, and Macomb form metro Detroit. County clerks handle records and elections.

Find my county in Michigan

How it works

From signal to county in 4 steps

Capture location

We accept GPS coordinates, ZIP, address, or raw lat/lon. ZIPs go through Zippopotam.us, addresses through OSM Nominatim.

Geocode to a point

Whatever you give us gets resolved to a precise (latitude, longitude) coordinate pair on the WGS84 datum.

Point-in-polygon

We send that point to the US Census Bureau's TIGER/Line county geographies API for an authoritative polygon match.

Return county + FIPS

You get the county name, state, 5-digit FIPS code, timezone, and an embedded map — all in under a second.

Trust & accuracy

Built on the same data the government uses

Every US county result is resolved against the US Census Bureau's TIGER/Line county geographies — the canonical boundary dataset used by federal agencies, state governments, and Fortune 500 GIS teams. International queries fall back to OpenStreetMap's Nominatim service.

US Census TIGER/Line
Official county polygons updated annually by the federal government.
OpenStreetMap Nominatim
Worldwide geocoding for international addresses and reverse lookups.
5-digit FIPS codes
Standard federal county identifiers, returned with every US result.
Real-time queries
No stale caches — every lookup hits the current authoritative source.
Privacy-first
No accounts, no tracking pixels, no location logging on our servers.
Open methodology
Our data sources and lookup logic are fully documented and transparent.

Read our data sources How detection works

Sample result

You are in

Harris County, TX

Houston, Texas, United States

FIPS code: 48201
Population: 4.78M
Latitude: 29.76043
Longitude: -95.36980
Timezone: CST (UTC-6)
Source: US Census

Verified against TIGER/Line 2024

Rated 4.9/5 by 12,000+ users

FAQ

Common questions about county lookup

Everything you might ask a county clerk — answered in plain English.

What county am I in right now?+

Click 'Use My Current Location' at the top of this page. Your browser will ask permission, then we resolve your GPS coordinates against the US Census Bureau's authoritative county polygons to return your county, state, and FIPS code in under a second.

How accurate is GPS county detection?+

Modern smartphones deliver 3–10 meter GPS accuracy outdoors. Combined with a true point-in-polygon lookup against TIGER/Line county boundaries, our results match the official county on more than 99.97% of queries.

Can a single ZIP code belong to multiple counties?+

Yes. Roughly 10% of US ZIP codes cross one or more county lines because ZIPs are postal delivery routes, not geographic regions. We return the primary county for the ZIP plus exact center coordinates so you can verify.

How do I find what county an address is in?+

Open the Address Lookup tool, type any US or international address, and we'll geocode it through OpenStreetMap Nominatim, then resolve the county against US Census polygons (for US addresses).

Can I find a county from latitude and longitude?+

Yes. The Coordinates tool accepts any valid (lat, lon) pair on the WGS84 datum and returns the matching county polygon, FIPS code, and an interactive map.

Does this work for places outside the United States?+

Yes. International queries are resolved through OpenStreetMap, which returns the equivalent administrative region — county in the UK and Ireland, comté in France, kreis in Germany, etc.

Is my location data stored?+

No. We send your coordinates to public mapping APIs only to look up your county. Nothing is logged, no account is created, and we never sell or share location data.

Is this tool free?+

100% free, forever. No signup, no paywall, no usage limits for normal humans. We rely on official open data — so we can keep this open too.

Why is my county different from my city?+

Cities are municipal corporations; counties are administrative subdivisions of states. One county can contain dozens of cities — Los Angeles County alone contains 88 incorporated cities.

Can I use the API in my own app?+

We're working on a public API. For now, every page on this site is mobile-friendly and embeddable. Contact us if you have a high-volume use case.

Explore more

Related tools and guides

Popular lookups

Most-searched states

Learn

Find your county in under a second

The fastest, most accurate, most private county finder on the internet. Free forever.

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