Convert pixels into square microns



I have drawn a selection on an image with this program. The obtained area is in pixels, but I would like to turn it into square microns. How is this possible? The example I have is:
Area. 17662.597
Resolution: 0.333 pixels per µm
Pixel size: 3.00x3.00 µm

Thanks in advance!


You will find all info you need here. Spoiler: first use Analyze>Set Scale on a known distance measured using the line tool.


If you want to convert a pre-measured area in pixels to calibrated units, just multiply it by the pixel size squared.

In your example 17662.597 pixels and a pixel size of 3um is equal to 158963.373 um^2 (that is 17662.597 * 3 * 3)