<prompt> Human: I have a 35,300 private loan at a 9.5 interest rate and a 28,000 federal loan at a 4.4 interest rate. My total payment per month is about 742. I plan on paying 1500 a month for the first couple years as I am living at home and saving money on rent. Im wondering what the best plan of attack is and what will cost me the least interest with the extra 758 on principal. Do I put it all towards the private loan or only a portion?If anyone has refinancing tips that would be great. Ive looked into SoFi and other options, but if anyone has more knowledge into the best option please let me know. Thank youEdit: these are both 10 year termsMinimum payment: Federal-291 option for graduated is 163-490 Private-451Assistant: Mathematically it will cost the least amount of interest to pay the minimum on you Federal 4.4 loan and the rest of the 1500 on the private loan. Keep doing this until you 1. refinance and get rid of that ridiculous 9.5 rate2. pay off the 9.5 loan. To get more info on why this is mathematically your best option you can check out the tool at unbury.meHuman: Also do you know what would be the best refinance option? As in: would it be better to get a 5 year refi with a higher payment or a 20 year refi with a lower payment. If interest rates are held constant and the extra payment goes to that loan, do you know which would cost less in interest?  <response>: I would go with whatever interest rate is the lowest provided a 5 year payoff is even realistic. You can get a 20 year and pay it in 5 years. 20 year gives you more flexibility if you lose a job etc but if you get lazy because of it and do not pay aggressively you could simply be costing yourself money. 