Input your numbers in the calculator form , then click "calculate" to start comparing different debt payment scenarios. Note that you can either select the number of years to pay the debt off, or you can select the desired monthly payment (Select ONLY ONE). Do not use commas in the "Amount To Finance" field. Your results will appear under the yellow box on the right under "Compare Senarios". To add more payment calculations repeat the previous steps and the results will be added to the "Compare Senarios" field. When you are done generating values, click on the rows under the "Compare" heading to change their color. That way, you can group your options together for easy viewing.