All these calculations can be done using field coding and having the 'calculate on exit' property set for each of the input formfields. See the
Financial Calulations topic in my
Microsoft Word Field Maths Tutorial, which is in a 'Sticky' thread at the top of this page:
https://www.msofficeforums.com/word/...-tutorial.html
And, to see how to do just about everything else you might want to do with dates in Word, check out my
Microsoft Word Date Calculation Tutorial, which is in a 'Sticky' thread at the top of this page:
https://www.msofficeforums.com/word/...-tutorial.html