About the Student Loan Refinance Calculator
This student loan refinance calculator compares the loans you have now with a refinance offer from a private lender. Enter your current balance, rate and years remaining, then the new rate and term. It shows both monthly payments, the total you would repay under each option, the interest difference and — if the lender charges any fee — how long it takes for the savings to cover it.
Refinancing replaces one or more existing loans with a new private loan. A lower rate cuts interest, and a shorter term cuts it further, while a longer term lowers the monthly payment but can increase total cost even at a lower rate. The comparison makes that trade-off visible before you apply.
Be careful with federal loans: refinancing them into a private loan permanently gives up income-driven repayment, Public Service Loan Forgiveness, federal deferment and forbearance, and any future federal relief. The math here assumes fixed rates on both loans and no extra payments.
With the default inputs, the lifetime savings from refinancing is $4,698.59. Change any value above to recalculate instantly.
How to use the student loan refinance calculator
- 1Enter your current total balance and weighted-average rate.
- 2Enter how many years are left on your current repayment plan.
- 3Enter the refinance rate and term you have been offered.
- 4Add any refinance fee (most lenders charge none).
- 5Compare the monthly and lifetime savings before deciding.
Formula and method
Both loans are amortized with the standard payment formula using the same balance P. The current payment M₀ uses your current rate over the remaining months n₀; the new payment M₁ uses the refinance rate over the new term n₁. Monthly savings is M₀ − M₁.
Lifetime savings compares everything you would still pay: M₀ × n₀ on the current loan versus M₁ × n₁ plus any fees on the new one. Because the principal is the same in both, this equals the interest saved minus fees. Break-even is fees ÷ monthly savings.
- P
- Balance being refinanced
- M₀, M₁
- Current and new monthly payments
- n₀, n₁
- Months remaining now and new term in months
- r
- Monthly rate (annual rate ÷ 12)
Worked examples
$40,000 from 6.5% (8 yrs left) to 4.5% for 7 years
Your current payment is $535.45 for 96 months. Refinancing to 4.5% over 84 months raises the payment slightly to $556.01, but total repayments drop from about $51,403 to $46,705 — a lifetime saving of about $4,699.
Lower rate but longer term
Moving $50,000 from 7% over 7 years to 5.5% over 15 years cuts the payment by about $346 a month, but you would pay about $10,148 more in total because interest runs for twice as long.
Same term with a $300 fee
Keeping a 10-year term but dropping from 7.5% to 5.5% saves about $30.53 a month. The $300 fee is recovered in 10 months, and net lifetime savings are about $3,363.
Frequently asked questions
Is it worth refinancing student loans?+
It can be if you have stable income, good credit and mostly private loans or high-rate federal loans you are sure you will repay in full. A rate cut of even one or two points can save thousands, especially if you keep or shorten the term.
What do I lose by refinancing federal student loans?+
Refinancing federal loans with a private lender gives up income-driven repayment, Public Service Loan Forgiveness, federal deferment and forbearance, discharge protections and eligibility for any future federal relief. The switch cannot be reversed.
Does a longer refinance term save money?+
Not necessarily. A longer term lowers the monthly payment but spreads interest over more years, so total cost can rise even at a lower rate. Check the lifetime savings figure, not just the monthly payment.
Should I pick a fixed or variable refinance rate?+
Fixed rates stay the same for the life of the loan. Variable rates start lower but can rise with market rates. Variable can make sense if you will repay quickly; fixed is safer for long terms.
What credit score do I need to refinance student loans?+
Many lenders look for scores around the high 600s or above, plus steady income and a manageable debt-to-income ratio. A creditworthy cosigner can help you qualify or get a lower rate.
Results are estimates for educational purposes and are not financial advice. Rates, fees and terms vary — confirm with your lender or a licensed advisor before making decisions.