In OpenStreetMap, I have a multipolygon OSM feature with its relation ID
How do I calculate the area of a such features using QGIS?
You can download the
QuickOSM plugin in QGIS.
Then, in the
Query panel, use the following query:
This will give your polygon layer with the OSM object inside.
You can use the
Identify tool in QGIS, the small blue
i, click on your feature and then expand the
Derived information. You can find the area ellipsoidal in square meters.