Interest on a Direct Unsubsidized Loan starts accruing the day your school receives the disbursement. Not the first day of class, not graduation, not the day your first bill arrives. For loans first disbursed between July 1, 2025, and June 30, 2026, that daily interest runs at a fixed rate of 6.39% for undergraduates and 7.94% for graduate and professional students.1Federal Student Aid. Federal Interest Rates and Fees The federal government does not cover any of that interest for you, so every day between disbursement and your final payment adds to what you owe.
How the Daily Charge Is Calculated
Your servicer uses a simple daily interest formula:1Federal Student Aid. Federal Interest Rates and Fees
Daily Interest = (Outstanding Principal Balance × Interest Rate) ÷ 365.25 × Number of Days
Borrow $10,000 at 6.39% and the daily charge is roughly $1.75. Small on any given day, but it runs seven days a week, including weekends, summer breaks, and holidays. Over a four-year degree those charges pile up to well over $2,500 before you make a required payment. The principal figure in the formula is what to watch. If unpaid interest gets folded into principal through capitalization, the daily charge recalculates against the new, larger number.
Interest While You’re in School
As long as you’re enrolled at least half-time, you aren’t required to make monthly payments on a Direct Unsubsidized Loan.2Federal Student Aid. Subsidized and Unsubsidized Loans Interest still accrues every day. Summers count. Breaks between semesters count. Any term where you stay enrolled but drop your course load counts.
This is where unsubsidized loans differ sharply from subsidized ones. With a subsidized loan the government pays the interest while you’re in school. With an unsubsidized loan that cost is yours from day one of disbursement.
Interest During the Grace Period
After you graduate, leave school, or drop below half-time, you get a six-month grace period before your first payment is due.2Federal Student Aid. Subsidized and Unsubsidized Loans Interest keeps accruing through all six months. The grace period gives you time to find work and get your finances in order, but the balance continues to grow while you wait. By the time the first bill lands, you can owe noticeably more than you originally borrowed.
Interest During Deferment and Forbearance
Deferment and forbearance let you pause required payments for reasons such as economic hardship, military service, or a graduate fellowship.3Federal Student Aid. Grace Periods, Deferment, and Forbearance in Detail They stop the monthly bill. They do not stop the interest clock. On a Direct Unsubsidized Loan, you remain responsible for every dollar of interest that accrues during any deferment or forbearance.2Federal Student Aid. Subsidized and Unsubsidized Loans
A 12-month economic hardship deferment on a $20,000 balance at 6.39% adds roughly $1,278 in interest over that year. Cash flow relief is real, but the long-term cost is significant. Making even small interest payments during a pause keeps the balance from expanding.
When Unpaid Interest Becomes Principal
Capitalization is when unpaid accrued interest gets added to your principal balance. Future interest is then calculated on that larger number, which means you start paying interest on interest. A $20,000 loan that accumulates $3,000 in interest during school becomes a $23,000 principal at capitalization, and from that day forward the daily charge runs on $23,000 instead of $20,000.
Federal rules have narrowed the events that trigger capitalization on Direct Loans. Interest that accrues during your in-school period, the grace period, and forbearance is no longer automatically capitalized. It is tracked as an unpaid amount that increases your total debt without compounding. Capitalization still happens in certain situations, including when you exit a deferment on an unsubsidized loan and when you leave the Income-Based Repayment plan or stop qualifying for income-based payments.4Consumer Financial Protection Bureau. Tips for Student Loan Borrowers
Under earlier rules, capitalization happened routinely at the end of the grace period, so borrowers who entered repayment in prior years may have seen an automatic jump in principal. The current framework has fewer triggers, but the unpaid interest still exists and still has to be repaid. Paying it off before any capitalization event is the single most effective way to control your total loan cost.
How to Keep Interest From Growing Your Balance
You don’t have to wait until repayment begins to start pushing back on interest. Voluntary interest-only payments while you’re in school, during the grace period, or during deferment keep the balance from ballooning. By regulation, any payment is applied first to outstanding interest before it touches principal, so a small monthly payment goes straight to the accrued interest.
To see exactly how much unpaid interest has built up, log into your servicer’s account and pull up the loan detail. Most servicers let you schedule recurring payments targeted at a specific loan, which helps if you carry both subsidized and unsubsidized debt and want to focus on the one that’s actively accruing. Even $25 or $50 a month during school can save hundreds over the life of the loan.
The Tax Deduction on What You Pay
Interest you pay on a Direct Unsubsidized Loan may qualify for the student loan interest deduction, including voluntary payments made while you’re still in school. You can deduct up to $2,500 per year in qualified student loan interest, taken as an adjustment to income, so you don’t need to itemize.5Internal Revenue Service. Topic No. 456, Student Loan Interest Deduction
For 2026, the deduction phases out with modified adjusted gross income. Single filers get the full deduction at $85,000 or below, a partial deduction between $85,000 and $100,000, and none at $100,000 or above. Married joint filers get the full deduction at $175,000 or below, a partial deduction between $175,000 and $205,000, and none at $205,000 or above.
The deduction lowers the effective interest rate you’re paying. At a 22% marginal tax rate, a full $2,500 deduction saves $550 in taxes. If you make voluntary interest payments while in school, keep the records. That interest qualifies in the year you pay it, even before repayment officially begins.