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I am new with GIS.

Assume we use the UTM30N coordinate system.

Is it possible to calculate an area (say a square box) by the 4 given points? (assume the points are in order, and the coordinates are very close to each other.)

Corollary, is it possible to calculate the area of a polygon?

Can this be done without the use of PostGIS?

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    Using pencil and paper? Using a hand calculator? Using a spreadsheet? Can be easily done with all three if you assume the points are on a flat plane, which is true to a high degree of precision for close points. Lovely example in part 3 here: wikihow.com/Calculate-the-Area-of-a-Polygon Now, what are you actually asking? – Spacedman Jan 30 '15 at 19:02
  • Good point, sorry to not be clear. Given that the large nature of the coordinate points. What units do I use? – Bill Jan 30 '15 at 19:08
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    Use meters. UTM coordinates represent distance in meters from the zone's reference point. Here's a quick and simple overview: maptools.com/tutorials/utm/quick_guide – andytilia Jan 30 '15 at 19:18
  • As with any projection, there are scale issues to consider, see this very detailed answer. However, for small areas, you can simply work in meters and get the area directly as if you were on a 2D plane. – John Powell Jan 30 '15 at 21:24
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    Most GPS specific software has the ability to give you the area of a track or just with measuring tools between points. And loading your points into QGIS or some other GUI based mapping software would allow the same thing, as does pen-and-paper suggested by the other comments. So no, PostGIS isn't required (nor is GIS at all really), and speed, accuracy, and ease-of-use are all trade-off factors to be balanced for your desired purpose. – Chris W Jan 30 '15 at 21:32

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