Enter your loan balance, interest rate, and monthly payment to see exactly how your student loan interest breaks down. You'll get your daily interest accrual, first month's interest vs. principal split, total interest paid, and payoff timeline — so you can see what your debt is really costing you.
Daily Interest Accrued
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First Month's Interest
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First Month's Principal
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Total Interest Paid
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Total Amount Paid
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Payoff Time
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Most federal student loans use simple daily interest, meaning interest accrues on your principal balance each day based on your annual rate divided by 365. Private student loans may compound interest, which means unpaid interest gets added to the principal and then accrues more interest — making them more expensive over time.
Daily interest is calculated using the formula: (Loan Balance × Annual Interest Rate) ÷ 365. For example, a $30,000 loan at 6.5% accrues about $5.34 per day. Over a month, that adds up to roughly $160 in interest charges before any payment is applied.
Under certain Income-Driven Repayment (IDR) plans, the government may cover unpaid interest that exceeds your monthly payment — particularly under the SAVE plan. This prevents negative amortization where your balance grows even as you make payments. Check current federal program rules, as policies change.
Yes. The IRS allows you to deduct up to $2,500 in student loan interest per year, subject to income limits. For 2024, the deduction phases out for single filers earning between $75,000 and $90,000, and for joint filers between $155,000 and $185,000. This deduction is taken as an adjustment to income, so you don't need to itemize.
Federal student loan interest rates are set by Congress and cannot be negotiated down once issued. However, you can refinance into a private loan at a lower rate if you have strong credit and income — though you'd lose federal protections like income-driven repayment and forgiveness programs. Enrolling in autopay also typically earns a 0.25% rate reduction.
Often yes. IDR plans lower your monthly payment based on your income, which means more of each payment goes to interest and your principal shrinks more slowly. This extends your repayment period and increases total interest paid — unless you qualify for loan forgiveness after 20–25 years, which cancels the remaining balance.
Even a small extra monthly payment significantly reduces total interest and payoff time. For example, paying an extra $100/month on a $30,000 loan at 6.5% can shave years off repayment and save thousands in interest. Use the extra payment field above to model your own scenario.
During most deferment and all forbearance periods, interest continues to accrue on unsubsidized loans. This unpaid interest may capitalize (be added to your principal) when the deferment ends, increasing your total loan balance. Subsidized federal loans don't accrue interest during qualifying deferment periods.