Apply any monthly savings to the principal of your remaining student loans. In addition to trading in a high interest loan for a low interest cash advance, making extra payments utilizing a cash advance, I place the extra $153 towards the principal balance of my loan to realize even more interest savings. By recalculating my monthly payment as explained above I now have a $153 buffer for any expenses that may come up. At the moment, I use this $153 buffer to further pay down my loan. This is an extra $1,836 for one year and over the life of the loan it is an additional $18,360! This can shave some serious time off your loan. While there are so many factors that affect your loan repayment, I find mortgage payment calculators very helpful here. A mortgage payment calculator allows you to calculate how making an additional payment each month will shorten the length of your loan.