All federal student loans have a variable or fixed interest rate that is set by Congress. The interest rate will vary depending on the type of loan you borrow and when the loan disburses. In most cases, if you have borrowed a loan since 2007, your loan will have a fixed interest rate. This means the interest rate will remain the same for the life of the loan or until it is completely repaid.
The amount of interest that accrues (accumulates) on your loan from month to month is determined by a simple daily interest formula. This formula consists of multiplying your loan balance by the number of days since the last payment times the interest rate factor. The interest rate factor is determined by dividing your loan’s interest rate by the number of days in the year. (Federal Student Aid)
Simple daily interest formula:
Outstanding principal balance
X number of days since last payment
X interest rate factor
= interest amount
Interest will accrue while you are enrolled in school. However, if you have a Federal Direct Subsidized Loan, the government will pay the interest that accrues while you are in school as long as you are enrolled at least half-time.
If you borrow a Federal Direct Unsubsidized Loan or Federal Direct Grad PLUS Loan you will be responsible for paying the interest that accrues while you are enrolled in school. Students enrolled half-time or more do have the right to receive an in-school deferment from their loan servicer. Students are still responsible for repaying the interest that accrues, but the payments are not due during the deferment period. Interest that accrues during a student’s deferment will capitalize (be added to principal amount borrowed). Capitalization occurs at the time you enter repayment and results in a higher amount to be repaid.