Decare and land area calculation app with square metres and measurement method
Decare calculation is simple as a unit conversion, but the measured boundary and method determine whether the result makes sense.
Field takeaways
- 1 decare is 1000 square metres.
- Boundary choice determines the area result.
- Walking measurements are reconnaissance, controlled survey is for professional delivery.
- Horizontal area and surface area should not be confused.
- MapLab Survey connects polygon area, notes and reports.
The units people actually mix up
A decare is 1,000 square metres and a hectare is 10,000. The old Turkish dönüm was roughly 919 square metres, which is why an inherited figure and a modern measurement rarely agree. Before arguing about a discrepancy, check that both numbers use the same unit. The conversion is the easy part — deciding which boundary you measured is the hard one.
Calculating the area in MapLab Survey
- Open the parcel or working boundary as a reference.
- Draw the polygon or record the boundary by walking it.
- Read the value in square metres, decares and hectares.
- Note the method: phone GPS, KML reference or RTK survey.
- Share the result as a report, KML, DXF or GeoJSON.
Occupation is not title
What you measure is the current use of the land. The registered area comes from the cadastral record and can differ; the cultivated area may exclude stones, tracks, ditches, trees or unused strips on top of that. All of these can be correct at the same time — they answer different questions, and the report should say which one it answers. Determining an official boundary is licensed survey engineering work; the app speeds up the field side and does not replace the side that signs.
Measure first, convert once
Walk or draw the boundary, read the area in square metres and convert once at the end. Converting halfway through a calculation is where rounding errors creep in.
Where the error comes from
Phone GPS accuracy, the number of polygon corners, boundary interpretation, the coordinate system and slope all affect the result. State the method and the expected accuracy next to the figure — a number is only meaningful together with how it was produced.
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
How many square metres is one decare?
1000 square metres.
How is decare calculated?
Divide square metres by 1000.
Is phone area calculation reliable?
For reconnaissance, not legal survey.
Why can title area and measured area differ?
Boundary and method differences.
Technical references
The field guidance in this article is aligned with the technical and official references below.
Related: Field area calculation · Land square metre calculation · Phone area measurement · MapLab Survey