Unit for tabulate area results in table?

[EllaWes13]

Hi!

So I use ArcGISPro on desktop and I used the tool "tabulate area" to calculate the amount of five different classes in a map. I got this table:

But what are the units in the table? Someone online said it's always square meters, another said it's pixels? Is there a way for me to check the unit or to convert whatever this is in ArcGIS Pro? Ultimately, I'd like the unit to be either square kilometers or hectares. The tabulate area was run on a satellite image of an area that had been classified into five classes using a training sample before.

Thanks for any and all help!

[DanPatterson · Accepted solution]

You should really interpret the results in light of what you specified in the tool and inputs to the tool.

There are many factors that will determine what the actual cell size is in the table

Tabulate Area (Spatial Analyst)—ArcGIS Pro | Documentation

It is a bit of a read, but you will have the answer once you establish the aforementioned

[EllaWes13]

Thank you for this answer! The article you linked did help a lot!

[piiakoo · Accepted solution]

To my understanding, the units are the same as the units of the raster you calculated. The tool calculates the number of pixels within each value (or class in your case) and multiplies it with the pixel size.

For example, if I have a raster with 25 m pixels, the results of the Tabulate Area -tool are in m2. If I have 10 pixels with value 1, 20 pixels with value 2 and 30 pixels with value 3 within the zone features, then the results are:

Zone ID	Value 1	Value 2	Value 3
1	10 * 25m * 25m = 6250 m2	20 * 25m * 25m = 12500 m2	30 * 25m * 25m = 18750 m2

Note that this does not necessarily apply to other tools.

[EllaWes13]

Thank you for this answer! Thanks for also showing some example calculations, it really helped seeing it to understand my results!