While in the editor of your template you'll want to first choose calculated field to add to your template.
*Note: If you're the company admin you can also create calculated fields within the dataset.
Next, choose the type of calculation you want to do.
With the first field in blue I will select the element from my template in the drop down that I want to add to the equation.
Now to enter in the second field to the equation you'll want to click in the empty cell to the right then choose to either search (magnifying glass) for a new field to pull into the equation or to enter in a custom value by clicking on the >_ icon (for example, maybe I want to take the Average Balance field and + 12 I could choose the custom field and then enter 12 in the empty cell to the right of my Average Balance field)
(Example of a custom value entered, clicking on the >_ icon)
(Example of selecting another element, clicking the magnifying glass)
You are not limited to only have two fields in a calculation. After you've created your initial two you can then click on any of the calculation icons to continue adding to your equation. Note that adding a very large (20 or so) number of component elements to a calculated element can cause browser errors.
You can also remove fields from the calculation by clicking on it then clicking on the trash icon.
Once you are done editing all of the fields (title, description, calculations, etc.) click on the create button.
Calculated fields are a powerful, advanced tool. It will take some technical knowledge (and definitely patience) to understand it. If you need help along the way, we are happy to point you to Knowledge Base articles and to provide quick responses. We also can make ourselves available for web training/help via our consulting services offering (chat with us to find out more).