In the past few years, we have covered a whole host of calculators for WordPress. If you run a real estate website, you should consider adding a mortgage calculator to your site. Reactive Mortgage Calculator gives your visitors a chance to calculate their mortgage numbers.
Your visitors will be able to play around with home value, downpayment, amortization period, annual property tax, insurance, monthly HOA, and other factors to get a monthly breakdown of their payments. The plugin also puts your data a pie chart.
This plugin allows webmasters to use multiple instances with different values. It is available as a free download.