<prompt> Human: Hi,I had asked earlier this week about the viability of paying a mortgage earlier and received some positive feedback.I was thinking about it and theres one thing that confuses me - I remember someone explaining that your mortgage payments are planned so that you pay the interest first and slowly include more and more of the principle until the interest is paid off.If thats the case, how is it even possible to minimize the amount of interest you pay?Lets say the mortgage is for 300k at 5 interest for 30 years.Assuming that the goal is to pay it off as soon as possible so the interest paid is minimal - using a mortgage calculator it says that the total cost is 580k - putting the interest at 280k.Since the monthly payments are built with that in mind - arent I just paying the whole 580k, but quicker?Im sure Im just missing something here.Thanks for any advice!EDIT: Thank you very much everyone! I get it now - any extra money you put in every month SHOULD go towards the principal, leading to the interest being recalculated and becoming lower. A few things to watch out for are the pre-payment penalties and the bank trying to screw you over by applying your extra payment towards interest rather then principal. Thanks again!  <response>: So this is a fun little calculator that graphically shows you how your interest and principle are affected by early payments. Over the course of the loan, it can seriously add up. 