Find out what kind of variable interest loan you have. If you have a Stafford loan, see Steps 2 and 3. Otherwise, skip to Step 4.
Find the 91-day T-bill rate for the last auction in May and add 1.7 percent. This is the interest rate while you are in school, during the grace period and while the loan is in deferment.
Take the 91-day T-bill rate for the last auction in May and add 2.3 percent. This is the interest rate while the loan is in repayment.
Do you have other variable interest student loans? The normal way that banks determine your interest rate is to add a percentage to the prime rate, which is set by the federal government.
Have you consolidated your student loans? In this case, the interest rate is based on the existing rates of the loans.