Calculations in Weflow work for any kind of currency field. So, even if you have custom fields set up (for example: margin or a calculation based off different products being added to an opportunity) this will work for you.
How to use calculations in your pipeline
Go to a pipeline view of your choice
Make sure to have a currency field added (if you don't, go to "Columns" and look for i.e. "Amount", "Expected Amount", "Margin" or something similar)
At the bottom of the column, you can make a calculation which will be based off the entire column
You can choose between SUM, MAX, MIN and AVERAGE