Calculate area of polygon with AreaCalculator and other but they all generates incorrect result, coordinate system is EPSG:3857, Workspace and Data are attached. Not sure what I am doing wrong

Try using the GeographicAreaCalculator from the FME Hub and specify a local projection for the area which you're calculating.

Hello David,

In the workspace I have included a test with GeographicAreaCalculator but still incorrect results. No sure what I am doing wrong since the transformer has high reviews. For reference a polygon named "sycklinge 1:22" is supposed to be 1265 square meters but the result I get from the transformer is an area of "1.9299688569405845e-7"

I'm fairly certain this is a projection and/or coordinate system issue, not a problem with the transformer.

The GeoJSON has a header that says it's in EPSG:3857, but can we be 100% sure? Looking in the GeoJSON, the coordinates seem to be in degrees, not meters which is what EPSG:3857 would indicate.

Try overriding the coordinate system on the reader to "LL84" and see if the results make more sense.

Thank you David, this solved the issue!