The two types of private loan interest rates are fixed-rate and variable-rate. The interest rate on fixed-rate loans won't change for the duration of your loan, while the interest rate on variable-rate loans can rise and fall with the market. The perk of variable-rate loans is that their interest rates can start lower and remain lower than fixed-rate loans throughout the life of the loan. This is not a guarantee, however, as interest rates can also rise above those of fixed rate loans, increasing your monthly payment and overall loan amount. Fixed interest rates are generally a safer bet for student loan borrowers, although finding a good deal on a variable rate might make sense if you’re only taking the loan for a short period of time, or if interest rates are expected to fall.