# [postgis-users] Computing area in km^2 from 4326 geometries

Ethan Alpert ealpert at digitalglobe.com
Tue Sep 28 15:11:43 PDT 2004

```I'm getting degrees^2 because my geometry is in lat/lon afaict.

-e

-----Original Message-----
From: postgis-users-bounces at postgis.refractions.net
[mailto:postgis-users-bounces at postgis.refractions.net] On Behalf Of
Craig Miller
Sent: Tuesday, September 28, 2004 4:07 PM
To: 'PostGIS Users Discussion'
Subject: RE: [postgis-users] Computing area in km^2 from 4326
geometries

If the area function is returning square meters (depends on your
projection) then just divide the answer by 4046.896 to get kilometers.

All area functions are squared by definition.

--Craig

________________________________

From: Ethan Alpert [mailto:ealpert at digitalglobe.com]
Sent: Tuesday, September 28, 2004 2:57 PM
To: PostGIS Users Discussion
Subject: [postgis-users] Computing area in km^2 from 4326
geometries

How does one compute areas in km^2? I was thinking something
like area2d(transform(the_geom,<someEPSG>)).

How do others do this?

Thanks!

-e

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