I have a Shapefile that has properties/parcels as polygons. I am looking to select by parcels that are bigger than a certain size in acres. The problem is that the Shapefile has the properties/parcel sizes in BOTH square meters and acres. Some are in square meters and others are in acres, and there is a column that indicates whether the value is in acres (A) or if it is in square meters (S). Is there a formula that I can enter to create a new column that converts all of the numbers that are in square meters into acres?
As the suggestion says, use one of the geometry functions in QGIS to get the area in consistent units, probably in a new column. The units will be dependent on the projection - i.e. the area will be the squared units of the projection. I think if it's in lat lon it will be approximated to metre units.