Area measurement app: square metre, decare and perimeter on a phone
People searching for an area measurement app usually want a quick answer: how many square metres, decares or metres of perimeter.
Field takeaways
- The boundary source must be clear: GPS walk, manual drawing, KML/DXF or RTK measurement.
- Phone GPS is useful for approximate area, not official parcel area.
- 1 decare is 1000 m2 and 1 hectare is 10,000 m2.
- The polygon must close for a reliable area.
- MapLab Survey keeps area, perimeter, notes, photos and export in one project.
Three practical ways to measure an area
On a phone there are three common routes: draw the boundary by hand on the map, walk it and build a polygon from the GPS track, or open an existing KML/DXF and check the area it encloses. Which one is right depends on the job. For a garden fence, an irrigation plan or scouting, phone GPS can be enough; for an official parcel, expropriation, court evidence or precise payment measurements, authorised surveying is required.
The quick flow in MapLab Survey
- Open a new project and name the job.
- Create an area layer: "field area", "stockyard", "parcel reference".
- Draw the boundary, walk it with GPS, or import the KML/DXF.
- Close the polygon and read the area and perimeter.
- Export the result as KML, DXF, GeoJSON, CSV or a report.
Square metres, decares and hectares
Units are where field conversations go wrong most often. The square metre is the technical base; the decare — 1,000 square metres — dominates farmland talk; the hectare is 10 decares and appears on larger areas. Keep the unit explicit in the project note, and later readers will not have to guess.
The result is only as good as the boundary
An area figure cannot be more accurate than the line it is computed from. If the GPS weakens under trees, if the polygon zigzags, or if the wrong parcel line was used as the base, the area is off too. That is why professionals leave a note beside the number: "approximate, by phone GPS", "from KML reference", "from corners measured with RTK".
Close the ring before you trust the number
An open polygon reports a wrong area and a wrong perimeter without warning. Check the closure, look at the shape for accidental crossings, and only then read the figure — a number that looks impossible is almost always a geometry problem, not an arithmetic one.
See it in action
The Ultimate Mobile GIS App for Surveyors & Engineers | MapLab Survey
Visit the YouTube channel ->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
What should an area app support?
Area, perimeter, layers, KML/DXF export, offline use and CRS support.
Is phone area measurement accurate?
Useful for approximate work, not official surveying.
Can MapLab Survey export KML?
Yes, KML/KMZ, DXF, GeoJSON and CSV are supported.
What is 1 decare?
1000 square metres.
Technical references
The field guidance in this article is aligned with the technical and official references below.
Related: Field area calculation · Phone area measurement · How to measure land · MapLab Survey