How to measure land with Google Earth, KML and field checks
Google Earth is useful for visual checking, but imagery on screen is not the same as an official or centimetre-level survey.
Field takeaways
- Google Earth is strong for visual review and KML sharing, not legal surveying.
- KML is interpreted in WGS84 geographic coordinates.
- Area results depend on drawing quality, imagery and CRS handling.
- MapLab Survey turns KML into a field layer with notes, photos and exports.
- For delivery, keep CRS and control notes with the KML.
When Google Earth is enough
Seeing roughly where a field sits, sketching a working boundary, sending a client a KML, or studying roads and access before driving out — Google Earth is a practical tool for all of it. Crews that want a fast look at the roads, streams, buildings and vegetation around a parcel get a good start here.
What you are actually measuring
A polygon drawn in Google Earth measures the image, not surveyed ground. The imagery may be old — the capture date is displayed, and a boundary drawn on a three-year-old image can ignore a new road or building. The parcel data may be generalised, and the image itself can carry an offset. The area inherits all of it without warning.
Carrying the KML into the field
- Take the KML/KMZ boundary from Google Earth or the sender.
- Open a project in MapLab Survey and add it as a reference layer.
- Name the layer plainly: "Google Earth reference", "parcel KML", "scouting boundary".
- Walk the boundary on site; add photos and notes at the critical corners.
- Add the coordinate system note before sharing as KML, DXF, GeoJSON, CSV or a report.
Care with the area figure
A Google Earth polygon gives an approximate area. Few corner points, a badly followed boundary, or horizontal area confused with surface area on a slope all change the result. A professional delivery states how the area was computed, in which coordinate system, and what was checked in the field.
The realistic workflow
Google Earth for the desk study, MapLab Survey in the field, RTK or proper survey equipment for the precise work. For official boundaries, stake-out or any figure entering a contract, the starting point is a field measurement — the screen line only ever points the way there. Determining an official boundary is licensed survey engineering work; the app speeds up the field side and does not replace the side that signs.
Try these steps on your own phone.
MapLab Survey handles RTK/GNSS point capture, drawing, area and volume calculations and coordinate conversion, then exports to DXF, KML/KMZ, GeoJSON, Shapefile, GeoPackage, NCZ or CSV. Capture, calculation and export work offline. Live NTRIP corrections and online basemaps need a connection.
Frequently asked questions
Is Google Earth land measurement official?
No. It is a visual and preliminary tool.
Can MapLab Survey open Google Earth KML?
Yes, as a reference layer.
Is Google Earth area accurate?
It can be useful for rough checks, not controlled survey delivery.
Why can KML look shifted?
CRS handling, imagery age and phone GPS error may cause offsets.
Technical references
The field guidance in this article is aligned with the technical and official references below.
Related: Open KML file · Create KML file · How land measurement works · MapLab Survey