Student Loan Calculator
Calculate your student loan monthly payment, total interest, and how much extra payments save. Works for federal and private student loans.
Every extra dollar goes to principal
How to use this calculator
Enter your total loan balance, the interest rate, and the term. The calculator shows your monthly payment on the standard plan, total interest, and what an extra monthly payment would save. If you have multiple loans at different rates, run this once for each — or use the highest-rate loan as an approximation.
Federal loan interest basics
Federal direct loan rates are set each July based on the 10-year Treasury note. Recent undergraduate rates: 5.5-8.05% depending on year. Rates are fixed — once you borrow, the rate is locked for the life of that specific loan. Graduate loans (GradPLUS) and private loans typically run 1-3% higher.
Repayment plan options (federal)
Standard: 10-year fixed, lowest total interest. Graduated: Payments start lower and increase every 2 years. Extended: 25-year term, lower monthly but much more interest. SAVE / IBR / PAYE (income-driven):10-25% of discretionary income, forgiveness after 20-25 years (or 10 with PSLF). Income-driven is a lifeline if your payment exceeds what you can afford — but it increases total interest if you'll eventually pay off the balance anyway.
Should you pay extra?
For federal loans, the math is straightforward: pay extra if your loan's rate exceeds your expected long-term investment return AND you're not pursuing PSLF. For most borrowers with rates 6%+, extra payments are a guaranteed risk-free 6% return — hard to beat. If you're on PSLF, extra payments are wasted (they reduce your balance before forgiveness) — pay the minimum.
Avoiding the minimum-payment trap
The 25-year extended plan may sound appealing (lower monthly payment), but on a $35,000 loan at 6.5%, you'd pay roughly $36,000 in interest over 25 years vs about $12,000 over 10 years. Always run both scenarios and pick the shortest term your budget can reliably handle.
Frequently asked questions
What's the difference between federal and private student loans?▾
Federal loans have fixed rates set by Congress, offer income-driven repayment plans, forgiveness options (PSLF, teacher forgiveness), and deferment/forbearance protections. Private loans are bank-issued, usually have variable rates, no income-driven plans, and far fewer protections. Always exhaust federal before private.
Should I refinance federal loans to get a lower rate?▾
Caution: refinancing federal loans into a private loan permanently forfeits income-driven repayment, PSLF, and most deferment protections. Only refinance if you're confident you won't need these benefits (high stable income, private-sector career, no plans to pursue PSLF). A 1% rate savings isn't worth giving up $100K+ in potential forgiveness.
What's the standard repayment plan?▾
For federal loans, the Standard Repayment Plan is 10 years of fixed monthly payments. Most borrowers default to this unless they enroll in an income-driven plan (SAVE, PAYE, IBR). Private loans typically offer 5, 10, 15, or 20-year terms.
Do extra payments help with federal loans?▾
Yes — federal loans have no prepayment penalty. Extra payments must be applied to the highest-interest loan; call your servicer or mark it explicitly or the payment will be spread across all loans. $100/month extra on a $35k balance at 6.5% over 10 years saves roughly $2,000 in interest.
What about Public Service Loan Forgiveness (PSLF)?▾
If you work full-time for a qualifying government or 501(c)(3) nonprofit, 120 qualifying payments under an income-driven plan forgive your remaining federal loan balance tax-free. This is the single highest-leverage move for many borrowers in qualifying jobs — pay the minimum on income-driven, do NOT refinance, and track your 120 payments carefully.
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