Student Loan Calculator
Student loan repayment depends on your balance, interest rate, and repayment term. The standard plan spreads payments over 10 years — but extra payments can cut years off your loan and save thousands in interest.
Enter your loan balance, interest rate, and term to see your monthly payment, total interest paid, payoff date, and a year-by-year amortization breakdown.
| Year | Principal | Interest | Balance |
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How Student Loan Repayment Works
A student loan is a standard amortizing loan: each monthly payment covers that month's interest first, then the remainder reduces principal. Early in the loan, most of each payment goes to interest because the balance is high. As the balance shrinks, the interest portion decreases and the principal portion grows — that's why making extra payments early has the biggest impact.
Standard vs. Extended Repayment
The federal standard repayment plan sets equal monthly payments over 10 years (120 payments). It minimizes total interest paid. Extended plans (20–25 years) reduce monthly payments significantly but can double total interest cost. For a $50,000 loan at 7%, the 10-year payment is about $581/month and total interest is ~$19,700. The 25-year payment drops to $354/month but total interest climbs to ~$56,200 — nearly the original loan amount again.
The Power of Extra Payments
Because student loans are simple interest loans (no prepayment penalty), every extra dollar you pay reduces the principal immediately and permanently lowers future interest charges. On a $30,000 loan at 6.5%, adding $100/month to the standard $340 payment cuts repayment from 10 years to ~7.5 years and saves over $2,000 in interest. Even rounding up your payment — from $340 to $400 — has a meaningful compounding effect over time.
| Extra / Month | Total Payment | Payoff Time | Total Interest | Interest Saved |
|---|---|---|---|---|
| $0 (standard) | $340 | 10 years | $10,748 | — |
| +$50 | $390 | 8 yr 10 mo | $9,271 | $1,477 |
| +$100 | $440 | 7 yr 10 mo | $8,085 | $2,663 |
| +$200 | $540 | 6 yr 1 mo | $6,257 | $4,491 |
| +$500 | $840 | 3 yr 10 mo | $3,818 | $6,930 |
Federal vs. Private Student Loans
Federal student loans come with income-driven repayment (IDR) options — plans that cap your monthly payment at 5%–10% of discretionary income. Private loans from banks or credit unions don't offer IDR, but often carry lower rates for borrowers with strong credit. This calculator works for both: enter your actual balance, rate, and term. For federal IDR plans, use the official loan simulator at studentaid.gov for the most accurate IDR payment estimate.
Refinancing to a Lower Rate
If you have private loans or a mix of federal and private loans, refinancing can reduce your interest rate significantly — potentially from 7%–8% down to 4%–5.5% for well-qualified borrowers. On a $40,000 balance with 8 years remaining, dropping the rate from 7% to 5% saves roughly $4,600 in total interest. The tradeoff for federal loans: refinancing into a private loan means losing access to IDR, Public Service Loan Forgiveness (PSLF), and other federal protections. For more strategies, see our guide on how to pay off student loans faster.
Loan Forgiveness Programs
Public Service Loan Forgiveness (PSLF) cancels the remaining balance after 120 qualifying payments (10 years) while working for a government or nonprofit employer. Income-Driven Repayment (IDR) plans forgive the remaining balance after 20–25 years of payments — though the forgiven amount may be taxable. Teacher Loan Forgiveness offers up to $17,500 for teachers in low-income schools. These programs only apply to federal Direct Loans. If you're targeting PSLF, do NOT refinance into a private loan — you'd lose eligibility permanently.
To explore strategies for paying down multiple debts alongside student loans, the Debt Consolidation Calculator can show whether consolidating helps — and the Debt Payoff Calculator lets you compare avalanche vs. snowball strategies across all your balances.
Frequently Asked Questions
How is a student loan monthly payment calculated?
Monthly payment = P × [r(1+r)^n] / [(1+r)^n − 1], where P is the principal, r is the monthly interest rate (annual rate ÷ 12), and n is total payments. For a $30,000 loan at 6.5% over 10 years: r = 0.065/12 = 0.005417, n = 120. Payment ≈ $340/month.
What is the standard repayment term?
The federal standard plan is 10 years (120 equal monthly payments). It minimizes total interest paid. Extended plans (20–25 years) lower monthly payments but substantially increase total interest — often by 2–3× on the same balance and rate.
Can I pay off my student loans early?
Yes — federal and most private student loans have no prepayment penalty. Every extra dollar paid goes directly to principal, reducing future interest. Even small extra amounts each month compound over time and can shave years off repayment.
What is the average student loan interest rate?
Federal Direct Loan rates for 2025–26 are approximately 6.53% for undergraduates, 8.08% for graduate students, and 9.08% for PLUS loans. Private loan rates vary widely — roughly 4%–14% depending on credit score, income, and lender. Rates are fixed for federal loans set each academic year.
Does paying extra reduce total interest on student loans?
Yes — extra payments directly reduce principal, which is the base interest accrues on. On a $30,000 loan at 6.5%, an extra $100/month saves over $2,600 in total interest and cuts repayment by more than 2 years. The earlier in the loan you make extra payments, the greater the benefit.
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