<prompt> Human: Hi all -I have been aggressively paying back student loans the past two years 2500month. I started at over 100k and I currently have 13,500 left of private loans24,500 of federal.My method for paying back has been paying the minimum on all loans, and paying 2500-SUMMIN of ALL LOANS on the loan with the highest interest rate. Now I thought this was the most efficient way to pay off my loans the quickest while paying the least interest. Playing with some numbers, it seems as though I was wrong.I am currently paying 2178.93month to private loans and 321.07month to federal loans. When my private loans are finished, I am switching to paying 1000month on my federal loans. I will be done with private loans March 2018, and about 24 months after that my federal will be gone.So current plan is all loans gone March 2020.If I were to switch my payment to 1500month at my private loans and 1000month on my federal, my private loans will be finished in 10 months or June 2018 and my federal will be finished about 26 months from now, or October 2019. Thats a difference of 6 months. If I were to pay 2500month towards federal loans, I would be completely done with loans 9 months from March 2018, or January 2019. So maybe I was correct in my original repayment method. I did not consider that I would be changing my repayment from 2500month to 1000month after private loans were gone.Did I mess up? What could I have done knowing I was going to pay 1000month on my federal loans eventually? Is there a way to figure out the optimal repay method knowing I want to switch to 1000month for federal loans? The reason for not continuing to pay 2500month is to start a savings account 1500month.  <response>: Paying the most towards the debt with the highest interest is mathematically the most effective way to pay the least interest. 