Student Loan Calculator
Calculate your student loan monthly payment, total interest, and payoff date for a fixed-rate repayment plan. See how extra payments reduce your total cost.
Formulas, assumptions, and rounding are documented in our calculator methodology.
Monthly Payment
$325.58
over 10 years
Loan Summary
- Monthly payment
- $325.58
- Total interest paid
- $9,069
- Total amount paid
- $39,069
- Payoff term
- 10 years
Fixed-Rate vs. Income-Driven Repayment
This calculator models fixed-rate, fixed-payment repayment — the standard plan for most private loans and the default federal plan. Income-driven repayment (IDR) plans like SAVE, PAYE, and IBR cap payments at 5–10% of discretionary income and forgive remaining balances after 20–25 years. IDR plans can save money for borrowers with high debt relative to income, but may result in more interest paid over time if you earn more later.
The Impact of Interest Rate on Total Cost
Interest rate has a major effect on total repayment cost. A $30,000 loan at 5.5% over 10 years costs about $7,700 in total interest. At 8%, the same loan costs about $11,600 — $3,900 more. Refinancing to a lower private rate can save money for borrowers with strong credit and stable income, but gives up federal protections like IDR eligibility and PSLF.
Subsidized vs. Unsubsidized Loans
Subsidized federal loans don't accrue interest while you're enrolled at least half-time or during deferment. Unsubsidized loans accrue interest from the day they are disbursed — including during school and grace periods. If you don't pay interest during school, it capitalizes (is added to principal) at repayment start, increasing your effective loan balance.
Frequently Asked Questions
- The standard federal repayment plan is 10 years (120 payments). Income-driven repayment plans extend this to 20–25 years with payments capped as a percentage of discretionary income. Graduated repayment starts with lower payments that increase every two years.
- Monthly payment = P × [r(1+r)^n] / [(1+r)^n − 1], where P is the principal balance, r is the monthly interest rate (annual rate ÷ 12), and n is the number of monthly payments (years × 12). This is standard amortization used for fixed-rate loans.
- Yes. Extra payments applied to principal reduce the balance faster, cutting interest charged on future months. On a $30,000 loan at 5.5% over 10 years, an extra $100/month saves about $1,500 in interest and pays off the loan 2 years early.
- Federal student loan rates are set annually by Congress. For 2024–2025: undergraduate Direct Loans 6.53%, graduate Direct Loans 8.08%, PLUS Loans 9.08%. Private loan rates vary by lender and credit score. Check your loan documents or servicer account for your exact rate.
- Up to $2,500 of student loan interest may be deductible per year for eligible borrowers, subject to income limits ($75,000 single, $155,000 married filing jointly for 2024). Consult a tax professional for your specific situation.