Yes you can, using the Web Viewer and a dataurl tag you can have calculations that will run the calculation you specify in the web viewer, with no need for a calculated field, enter the Web Address as:
"data:text/html," & Calc
I have put together a quick demo for some guys as work, it has a custom function that goes a bit further and has all the HTML and CSS for you to format the text, feel free to take it apart use it if it does the trick.
If you have any questions about the demo just ask.
I hope this helps
The ability to create layout level calculations does not exist in FileMaker. Using the web viewer as Orlando pointed out is one way of getting around that limitation.
FileMaker is very much contextual based and there is no true seperation of interface and data. In FM, you have table and then occurrences of those tables. Layouts are based on these table occurrences.
Thank you so much. I think that was exactly what I was looking for.