Mortgage rates are low, considering historical rates for the last 50 years. It may be timely to consider a mortgage refinance. The image above links to a simple tool for exploring mortgage refinance, built using rapache and the yet-to-be-archived yarr package for R. Hence, there are now two mortgage-related calculators on this site:
While I believe both calculators to be accurate, I make no guarantees. You are welcome to browse the source code (single file, mixed R and HTML/CSS) for either calculator: MortCalc.yarr, RefiCalc.yarr.