Hover the mouse over a point on the chart to get the associated numerical data
Use the "Add Loan" button to create additional loans for comparison
Select the chart timeframe by using the "# Years" buttons or select your own timeframe by entering values for Start and End. These two text entry fields take precedence (i.e., will override) the radio buttons.
You can also show a loan's repayment from the viewpoint of the APR but using the "Annual Percentage Rate" checkbox
Use the "Update Chart" button to refresh the chart for your new data
If you want to see the month by month comparison of loans, use the "Amortization" button. Please note, you will have to wait a moment or two for it to recalculate everything.