About

This tool is designed for logistics managers, real estate professionals, and urban planners who need precise spatial visualization without the complexity of enterprise GIS software. Unlike standard tools that limit you to a single radius, this application allows you to layer multiple concentric zones simultaneously (e.g., a 2 km free delivery zone inside a 10 km paid zone).

Accuracy is paramount in spatial planning. We utilize the Haversine Formula and geodesic calculations to account for the Earth's curvature, ensuring that a 10 km radius in Greenland is calculated with the same precision as one at the Equator. This is critical for defining legal boundaries, service contracts, or emergency response areas.

The tool operates entirely in your browser using OpenStreetMap data. Your location data is never sent to our servers. Furthermore, we solve the common problem of data portability: you can export your defined zones as GeoJSON files, making them compatible with Google Earth, ArcGIS, and QGIS.

Formulas

To calculate the distance d between two points on the Earth's sphere to determine if a location falls within a radius, we use the Haversine formula:

d = 2r arcsin√sin²φ₂ − φ₁2 + cosφ₁cosφ₂sin²λ₂ − λ₁2

Where φ is latitude, λ is longitude, and r is the Earth's radius (≈ 6,371 km).

Reference Data

Radius Distance	Approx. Area (km²)	Travel Mode (Avg)	Typical Use Case
0.4 km	0.50	5 min Walk	Public Transit Catchment
1.0 km	3.14	12 min Walk	15-Minute City Concept
5.0 km	78.54	15 min Cycle / 10 min Drive	Local Restaurant Delivery
10.0 km	314.16	20 min Drive	Urban Commute Limit
42.2 km	5,591	1 hr Drive	Marathon Distance / Metro Area
100 km	31,415	1.5 hr Highway	Regional Logistics Hub

Frequently Asked Questions

This is a result of the map projection (Mercator) used by most web maps. The Earth is a sphere, but the screen is flat. As you move away from the Equator, the map stretches. Our tool calculates the "Geodesic" circle (a true circle on the globe), which visually distorts into an oval on the map to accurately represent the real-world ground area.

Yes. Google Maps does not natively support "Circles" in import files, so our tool converts your radius into a precise Polygon (GeoJSON format). You can download this file and import it directly into Google My Maps, Google Earth Pro, or GIS software like QGIS.

While we use high-precision formulas (Haversine/Vincenty) accurate to within a few meters, consumer GPS devices and web maps can have offsets of 5-20 meters. For strictly legal surveying or property line disputes, you should always consult a licensed land surveyor.

Use the "Locate Me" button in the toolbar. The tool will request your browser's GPS position, plot a marker on the map, and the system will automatically alert you if that point falls inside any of the active radius circles.