This can be done by clicking your the container that has super tables on your dashboard.
On the left side of the data tab. There is pane that says calculation. Click make a calculation on there.
Navigate to the box that contains Calculation. Depending on your screen size you may have to scroll down.
You can now select any measure column that is present in the worksheet and make a calculation. To select a column press @ this will present a list of all available columns.
This is an example calculation to calculate the profit ratio.