[postgis-users] ST_AREA(geom) returns incorrect area

Håvard Tveite havard.tveite at nmbu.no
Fri Jun 26 13:13:25 PDT 2020

If you are using PostGIS Geometry, you will get the area in square
map units. With EPSG:3426 that means square degrees, so your numbers
sound reasonable.
With PostGIS Geography you would get a more "sensible" result.


On 13.06.2020 01:30, Clifford Snow wrote:
> When I run st_area(geom) against a geom in WGS84, my understanding is 
> that postgis returns the area in square meters. It's not. Instead it 
> returns something much smaller. The areas I'm interested in are small 
> bounding boxes so spherical measurements should be all that different.
> I verified that the table SRID is 4326. The boxes all display correctly 
> in both Pgadmin4 and QGIS.
> For example, a bbox around a house returns 9.84003999925341e-09. Yet 
> QGIS calculates it as 113.73 sqm. The QGIS calculation seems to be more 
> accurate.
> I know I'm doing something very wrong. Any help would be appreciated.
> Best,
> Clifford
> -- 
> @osm_washington
> www.snowandsnow.us <https://www.snowandsnow.us>
> OpenStreetMap: Maps with a human touch

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