In ArcMap, will Calculate Geometry (area) be accurate for records that have other polygons attached via Spatial Join? It doesn't seem to be adding the extra polygons that are spatially joined. ArcGIS 10.

However, my original Target shapefile, USFS Land Status layer, might have not excluded the areas for Fresh Water lakes in the first place even though the original attribute table breaks them out separately.

So either Spatial Join isn't adding the Fresh Water lakes in or the original Land Status Layer is counting the areas twice 1) within the area calculated for the land records and 2) in the Fresh water records. I had broken the original records apart via the Select tool and then did Spatial Join. enter image description here

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    did you calculate the area again after the spatial join?
    – yanes
    Oct 29, 2015 at 2:03
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    Yes I did and it doesn't equal the sum of the two columns. Thanks
    – MikeSEAL
    Oct 30, 2015 at 17:09
  • Thanks, I got your original post wrong, @paulo's answer below I believe is correct. By spatial join you are only transferring the attributes of the other layer that is spatially related (could be intersecting, proximity etc...) to your input layer according to your criteria. You will need to actually integrate/remove features as part of/from your input layer by either using union/clip tools depending on what you need to affect the area of your input features.
    – yanes
    Oct 30, 2015 at 19:41

1 Answer 1


Spatial Join doesn't add the geometries of the two layers together; it only adds the joined attributes to the target features (and their attributes) (see http://resources.arcgis.com/EN/HELP/MAIN/10.1/index.html#//00080000000q000000).

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