🎓 Student Loan Payoff Calculator

Enter your loan balance, APR, and monthly payment into the calculator above. It returns your exact payoff date and total interest, and lets you add an extra monthly payment to see how many months you cut off.

The calculator accepts multiple loan entries — you can input each loan separately with its own balance and interest rate, and the tool models the combined payoff timeline across all of them. This matters because most borrowers graduate with a mix of subsidized and unsubsidized federal loans from multiple years, often at different rates, and the total interest picture across all accounts is what determines your actual repayment cost. Entering each loan individually also reveals which one is costing the most in monthly interest, which informs the smartest order for extra payments.

On $35,000 in federal undergraduate loans at the 2025–2026 rate of 6.39%, the standard 10-year repayment plan produces a monthly payment of approximately $393 and generates roughly $12,160 in total interest — meaning you repay about $47,160 on a $35,000 loan. Increasing the monthly payment by $150 to $543 compresses payoff from 120 months to approximately 76 months and cuts total interest to about $6,300, a savings of nearly $5,900. The interest is front-loaded: in year one, roughly $2,200 of your payments go to interest and only $2,500 reduces the balance, which is why paying extra in years 1–3 produces disproportionately large long-term savings.

On a $35,000 balance at 6.39% APR under the standard 10-year plan, adding $150 per month reduces the timeline from 120 months to approximately 76 months — about 3.7 years sooner. Total interest drops from $12,160 to roughly $6,300, a savings of nearly $5,900. Even $75 extra per month on this loan saves approximately $2,800 in interest and pays it off 21 months early. The reason the savings are so large relative to the extra payment is that early principal reduction removes that balance from the compound interest base for every subsequent month — the effect is cumulative, not linear.

For the 2025–2026 academic year, federal student loan rates are 6.39% for undergraduate Direct Subsidized and Unsubsidized Loans, 7.94% for graduate Direct Unsubsidized Loans, and 8.94% for Direct PLUS Loans taken by graduate students or parents. These rates are set each July based on the 10-year Treasury note yield plus a fixed add-on set by Congress, meaning they change annually for new loans while existing loans retain the rate at which they were originally disbursed. Private student loan rates vary by lender and credit profile, typically ranging from 4% to 15% depending on whether the rate is fixed or variable.

For federal loans on income-driven repayment plans, the required monthly payment is calculated as a percentage of discretionary income — not based on what it takes to cover interest. When that payment is less than the monthly interest accruing on the balance, the difference is added back to the principal, causing the balance to grow even with on-time payments. This is called negative amortization, and it's a structural feature of income-driven plans, not a calculation error. On a $50,000 balance at 6.39% APR, monthly interest accrues at roughly $266 — if your income-driven payment is $180, the $86 shortfall adds to your balance each month.

Refinancing federal student loans into a private loan makes financial sense when you can secure a rate meaningfully below your current federal rate and you don't intend to use income-driven repayment, forgiveness programs, or federal forbearance protections. At current private refinancing rates of roughly 5–9% for well-qualified borrowers, refinancing a 7.94% graduate loan to 5.5% on a $40,000 balance saves approximately $3,200 in interest over 10 years. The permanent trade-off is surrendering federal protections — income-driven repayment enrollment, Public Service Loan Forgiveness eligibility, and the ability to pause payments during hardship. For borrowers in stable, private-sector careers with no intent to pursue forgiveness, the savings are real.

Aggressive payoff wins financially when your loan balance is manageable relative to your income and you won't qualify for meaningful forgiveness — the interest savings from accelerated payoff are real and compounding. Income-driven repayment wins when your balance is large relative to your income, when you work in public service and qualify for PSLF after 120 payments, or when your income is currently low enough that required payments are less than the interest accruing. The practical breakpoint is roughly a balance-to-income ratio above 1.5x: if you borrowed $60,000 and earn $40,000, income-driven repayment is likely the better structural choice; if you borrowed $25,000 and earn $65,000, aggressive payoff eliminates the debt faster than any forgiveness timeline.