field calculator - Is the derived area/length/xy values of a polygon/polyline layer in QGIS usable?

I have a raster that is projected to a state plane CRS and I am adding polygon/polyline shapefiles that are projected to WGS84. On the fly transformation is set to reproject to my raster CRS. When I use the identify features tool to select a feature, under derived I can see the correct area/length measurements. Is there a way to transfer that exact information into a new column(s) in the attributes by using the field calculator?