How GPS coordinates determine your county
A latitude/longitude pair is just a precise point on the Earth's surface. To turn that point into a county answer, our tool sends it to the US Census Bureau Geographies API, which runs a point-in-polygon check against the official TIGER/Line county boundary dataset — the same authoritative dataset used by federal redistricting, the IRS, FEMA, and state and local governments.
The result includes the county name, state abbreviation, full 5-digit county GEOID (FIPS code), and a map preview. The lookup runs in milliseconds and works for any coordinate inside US territory. For points outside the US we fall back to OpenStreetMap's administrative-boundary data.
Example coordinates and their counties
- 40.7128, -74.0060 → New York County, NY (Manhattan) · FIPS 36061
- 34.0522, -118.2437 → Los Angeles County, CA · FIPS 06037
- 41.8781, -87.6298 → Cook County, IL (Chicago) · FIPS 17031
- 29.7604, -95.3698 → Harris County, TX (Houston) · FIPS 48201
- 33.4484, -112.0740 → Maricopa County, AZ (Phoenix) · FIPS 04013
- 47.6062, -122.3321 → King County, WA (Seattle) · FIPS 53033
- 25.7617, -80.1918 → Miami-Dade County, FL · FIPS 12086
GPS accuracy and what it means for your county result
Modern smartphone GPS is accurate to roughly 3–10 meters outdoors with a clear sky view. Wi-Fi positioning on a desktop typically lands within 20–50 meters of the device. Indoor GPS can be much looser — sometimes hundreds of meters. Because US counties are large polygons (the smallest are several square miles; the largest are bigger than entire states), even loose GPS almost always produces the correct county answer.
The one edge case to watch for: standing within a few meters of a county line. In that situation, run the lookup again after walking 10–20 meters in either direction to confirm.
Where to get coordinates
- Google Maps — right-click anywhere; the lat/lon appears at the top of the context menu.
- Apple Maps — drop a pin, then read the coordinates in the location detail panel.
- iPhone Compass app — shows your current lat/lon at the bottom of the screen.
- OpenStreetMap.org — click "Share" and copy the geo URL.
- GPS receiver or drone telemetry — paste the recorded decimal coordinates directly.
Real-world use cases for coordinate lookup
- Field work & surveying — confirm county jurisdiction for environmental sampling, archaeology, or land surveying.
- Drone & UAV operations — county-level airspace and ordinance compliance checks.
- Outdoor recreation — hunters, anglers, and hikers verifying which county's permit rules apply at a given point.
- Insurance claims — adjusters mapping an incident coordinate to a county for jurisdiction and rate tables.
- Logistics & dispatch — matching GPS pings from vehicles to county-level service zones or tax jurisdictions.
- Public-safety dispatch — confirming which county sheriff or EMS service is responsible for a coordinate.
- Research & data science — joining a dataset of lat/lon observations to county-level demographics or policy data.
Step-by-step: how to use the coordinate lookup
- Type or paste the decimal latitude into the first field (e.g.
29.7604). - Type or paste the decimal longitude into the second field (e.g.
-95.3698). - Press Lookup. The county, state, and FIPS code appear in seconds.
- Open the embedded map to verify the point visually.
Frequently asked questions
How do I find a county from latitude and longitude?
Enter the decimal-degree latitude and longitude in the form above and press Lookup. We send the point to the US Census Bureau Geographies API, which performs a point-in-polygon match against the official TIGER/Line county boundary dataset, and returns the county name, state, 5-digit FIPS code, and a map.
What coordinate format should I use?
Decimal degrees. Example: 29.7604, -95.3698 (Houston, TX). Negative longitudes for the western hemisphere, positive for the eastern. Don't paste degrees-minutes-seconds (DMS) — convert to decimal first.
How accurate is coordinate-to-county lookup?
Essentially exact. County boundaries are stable, well-defined polygons and our match runs against the same dataset used by federal and state governments. The only source of error is the precision of the coordinate itself.
Does it work for coordinates outside the United States?
Yes. International points resolve to the equivalent administrative region (district, shire, oblast, municipality) via OpenStreetMap. US points additionally include the federal FIPS code.
Can I look up coordinates from Google Maps?
Yes. Right-click any point on Google Maps and the lat/lon appears at the top of the menu — paste those numbers into the field above to get the county.
What does FIPS mean?
FIPS = Federal Information Processing Standard. The full 5-digit county FIPS (also called the GEOID) uniquely identifies every US county: 2 digits for the state plus 3 digits for the county. Example: 06037 = Los Angeles County, CA.