<prompt> Human: I see on here and elesewhere that investing money into your mortgaged home is a return of what your interest rate is , like a gaurenteed 4 return.We are currently paying down our 30 year mortgage at a rate of 1.72 mortgage payments each month. This equals about 3 times the principle being paid off each month.When I look at amortization charts , the amount I have paid off at month 6 , is equal to month 17 if I had only made minimum payments. Doesnt that mean I have saved 11 full mortgage payments over the life of the loan? Thats way more then 4 - more like a 500 return. Am I missing something?  <response>: Your math isnt necessarily wrong it may be, I havent run the numbers but its also not helpful. The money youre spending on your mortgage could be spent somewhere else. You could spend it on investments getting 7. You could spend it on debt with 23 interest. You could spend it on things that lose value like cars, boats, planes, food, electronics, etc.The rate of interest or rate of return is the only fair way to compare ways to spend money. 