Instead of using three checkboxes, you should use a single dropdown with the three choices. That way, you don't need code to ensure two or more mutually-exclusive options aren't chosen. Furthermore, if you create the entire form using formfields instead of content controls, the whole lot can be done without VBA - using just field coding. To see how to do a wide range of calculations in Word, check out my
Microsoft Word Field Maths Tutorial, in the 'Sticky' thread at the top of this forum:
Microsoft Word Field Maths Tutorial