So ...

Upon activation, go to Settings => Resp Mortage Calculator to access the plugin configuration page:

You can start with adding the default values to display in the mortgage calculator fields that’ll help users understand the calculator’s functionality:

If you want, you can leave these fields blank, so the users can enter their own values to calculate the cost of a property.

Next, you can scroll down to the "Calculator Settings" section where you can customize the basic functionalities of your mortgage calculator (interest rate periods, currency symbol, currency code, formats, enabling down payment feature, etc):

Next, you'll have to define the payment period settings. These options allow users to calculate the down payments on periodical (annual, semi-annual, quarterly, monthly, etc) basis:

Next, you can scroll down to the layout & styling options, where you can select a theme for your mortgage calculator, add styling, enable/disable responsive setting, etc:

Finally, you'll be able to manage how you want to display the results and add labels for the calculator fields. Additionally, you can also create your own custom style settings to change the display of your mortgage calculator:

At the bottom of the page you'll find the "Input Classes" section where you can add your own CSS classes in order to override the default styles and CSS rules:

And that's it ... Once you are happy with your choices, click the "Save Changes" button to save your settings.

OK. Now let's see the result ...