How the area is calculated
Areas are geodesic: they are computed on the curved surface of the Earth (a spherical Earth model), not on the flat Web-Mercator map. That matters — on a flat map, a field in Norway would look more than twice as big as the same field near the equator. Perimeters and line lengths are geodesic as well.
Units
Switch between metric and imperial at the bottom of the panel:
- Metric: m² → hectares (1 ha = 10,000 m²) → km²
- Imperial: ft² → acres (1 acre = 43,560 ft²) → square miles
Tips for accurate results
- Switch to satellite imagery (layers button) to trace real boundaries, and zoom in as far as you can.
- Use more corners on curved edges; add corners later by dragging the small midpoint handles.
- Holes (a pond, a building) can be cut out with the Cut tool; their area is subtracted.
- Draw several shapes to see their total area at the bottom of the panel.
Measurements from imagery are estimates — for legal boundaries and sales, rely on a surveyor or the official cadastral record.