Frequently Asked Questions
Common questions about how the tool works, how accurate it is, and what it should and shouldn't be used for.
How accurate are the area measurements?
Measurements use Google's spherical geometry library, which accounts for Earth's curvature and is mathematically accurate to many decimal places. Real-world accuracy is bounded by two things: the resolution of the satellite imagery (typically 0.5–2 m per pixel in populated areas, coarser elsewhere) and how precisely you click the corners. For a parcel a few acres in size, expect roughly 1–3% error. Don't use this tool for legal property boundaries — hire a surveyor.
Is this tool free to use?
Yes. There is no signup, no paywall, no usage limit. The site is supported by ads on the surrounding content pages.
Do I need to create an account?
No. There are no accounts. Shapes you draw exist only in your browser tab and are discarded when you close it.
Can I save or export my measurements?
Not yet. The tool is currently session-only. Take a screenshot if you need to keep a record. Export to KML/GeoJSON is on the roadmap.
What units are supported?
Area: square meters (m²), square feet (ft²), acres, hectares, and square miles. Distance and perimeter: meters, feet, kilometers, and miles. You can switch units per shape using the dropdown next to each measurement.
How do I draw an irregular shape?
Click "Draw Area," then click on the map for each corner of the shape — as many as you need. Double-click on the last corner to close the polygon. After it's closed, you can drag any vertex to refine the shape.
How do I draw a circle?
Click "Draw Radius," then click and drag on the map. The starting point becomes the center; releasing sets the radius. After drawing, you can drag the edge to resize or drag the body to move it.
Why does the area look slightly different after I edit?
Editing a polygon (moving a vertex, dragging the body) recomputes the area in real time using the new shape. Small differences after a drag-and-release are expected because the underlying coordinates have changed.
Can I measure something that crosses an ocean or a continent?
Yes. Spherical geometry handles long distances correctly — measuring a polygon spanning hundreds of kilometers will give a meaningful answer that accounts for curvature. Imagery accuracy still applies, of course.
What does the AI assistant actually do?
The chat bubble lets you describe a shape in plain English ("draw a 5-acre circle near Boise, ID") and have it placed on the map. It's useful for quick sketches when you know the location by name. The assistant can also summarize what's currently drawn.
Does this work on mobile?
Yes. The interface adapts to phone screens. Drawing precision is naturally a bit lower with a finger than with a mouse, so for tight measurements a desktop or tablet with a stylus is recommended.
Why am I seeing a "Google Maps" library notice or error?
Google occasionally updates its Maps JavaScript API. If the map doesn't load or behaves oddly, try a hard refresh (Ctrl+Shift+R or Cmd+Shift+R). If the issue persists, please report it via the contact page.
Can I use measurements from this tool in court or for permits?
No. This tool is a planning aid, not a legal record. For property boundary disputes, building permits, or any official filing, you need a licensed land surveyor and recorded deed information.