15 year vs. 30 year loan comparison

This will calculate: what a 15 year loan really costs against a 30 year loan on the same amount, at 5, 10 and 15 years out.

The 30 year payment is lower, so the buyer keeps the difference every month. The question is whether that monthly saving, plus the slower principal reduction, beats paying the loan down faster. This works it both ways — with the monthly savings sitting idle, and with them invested at a money market rate.

Enter a money market rate to see how much reinvesting the difference changes the answer.