# Calculating Volume above and Below a designated elevation of a given area

Dionybell
Global Mapper UserPosts:

**33**Trusted User
Hello,

I've been assigned with calculating the volume on a raster surface of a polygon. I need to calculate how much volume (m3) is above 3.20 m and how much volume there is below the 3.20 m elevation.

I have a raster surface and the polygon.

Thanks in advance.

I've been assigned with calculating the volume on a raster surface of a polygon. I need to calculate how much volume (m3) is above 3.20 m and how much volume there is below the 3.20 m elevation.

I have a raster surface and the polygon.

Thanks in advance.

## Comments

33Trusted User71Start by adding the surface elevation values to your polygon (Select the polygon with the Digitizer, right click and choose Attribute/Style Functions > Apply Elevations from Terrain Layers to Selected Feature(s))

With the polygon selected, calculate the pile volume (Right Click on the map and choose Analysis/Measurement > PILE VOLUME - Calculate the volume of selected Piles/Areas).

Then limit the visible elevation of your terrain surface (Click on the options button in Overlay Control Center, and change the Maximum Valid Elevation in the Alter Elevation Values tab to 3.2m), you can then calculate the pile volume again to obtain the amount of the original pile volume that is below 3.2m.

Hope this helps!

Regards,

Josie