The result section of the calculators is meant to be sticky by default. If this is not working, it's usually because your website CSS has turned off.

A good example of a working installation is here: 
https://themortgageguyniagara.com/maximum-mortgage-calculator/

Please make sure that the top-level overflow is set to initial.

overflow: initial;

Also, if any CSS components that wrap the calculators have it set to hidden, please change it to "visible"

overflow: visible;

After you make it work and the result is now sticky under the menu, go here to adjust the top margin.

https://canadian-mortgage-app.helpshift.com/hc/faq/632-result-box-goes-under-your-website-menu/