See how much refinancing could save you in monthly payment and total interest — and what you'd give up if any of your loans are federal.
Federal-protections-lost warning verified against StudentAid.gov and CFPB guidance. Full methodology.
The calculator first works out what your current loan is actually doing at the payment you told it about — or, if you didn't enter one, the payment required to pay it off exactly on schedule, using the standard amortization formula. Then it simulates your current loan, payment by payment, over its remaining term to find its real trajectory: fully paying off on time, paying off early, barely covering interest with no progress at all (interest-only), still owing a balance at the end of the term, or — if the payment doesn't even cover the interest accruing each month — growing forever (negative amortization). The new loan is calculated the same way, using your new rate and term, with any origination fee added to the balance being refinanced. Unlike a mortgage, most private student loan refinancing carries no origination fees or closing costs, so this calculator defaults that to $0 and frames the comparison around lifetime interest saved, not a fee break-even.
Worked example, and the trap this calculator is built to catch: a $30,000 balance at 7% with 10 years left costs $348.33/month and $11,799.05 in total interest over those 10 years. An offer to refinance at a lower 5% rate but stretched to a 15-year term drops the payment to $237.24/month — a real, immediate savings of $111.09/month. But because it's spread over 5 extra years, that loan actually costs $12,702.86 in total interest — $903.80 more than sticking with the original loan, despite the lower rate. The calculator labels this “lower payment, higher total cost” rather than a savings, precisely because a lower rate and a lower payment can still add up to paying more over the life of the loan once the term changes.
Assumptions and edge cases: a lifetime-interest comparison is only shown when your current loan actually reaches $0 within its stated remaining term — if it's interest-only, negatively amortizing, or still has a balance left at the end of that term, there is no honest “total interest over the life of the loan” figure to compare against, and the calculator says so rather than guessing. Refinancing any federal loan into a private one is treated as irreversible: you permanently lose income-driven repayment, Public Service Loan Forgiveness, federal forbearance/deferment, federal loan cancellation programs, and (for eligible borrowers) the Servicemembers Civil Relief Act's 6% interest rate cap — shown as a standing warning whenever any federal loan is included, not just once. See the full methodology page for source citations.
Federal-protections-lost warning verified against StudentAid.gov and CFPB guidance.
See the full methodology page for how every calculator on this site is sourced and how confidence levels are assigned.
Limitations and disclaimer
DueMATH provides estimates for educational purposes only and is not tax, legal, or financial advice. Tax laws change frequently and every situation is different — confirm any number here with a licensed CPA, tax attorney, or your state's Department of Revenue before making a financial decision.
Refinancing a federal loan into a private loan is irreversible, and it forfeits every federal-specific protection: income-driven repayment plans, Public Service Loan Forgiveness, federal forbearance and deferment options, and federal loan cancellation programs (like borrower-defense or closed-school discharge). Private loans also typically don't offer death or disability discharge the way federal loans do, and if you took out your federal loan before military service, you'd lose the Servicemembers Civil Relief Act's 6% interest rate cap. None of this applies if you're only refinancing an already-private loan.
Usually not — this is one of the biggest differences from a mortgage refinance. Most private student loan refinance lenders don't charge origination fees or closing costs at all, so for most people the comparison is purely about interest rate and term, not recovering an upfront fee. A small number of lenders still do charge a fee, which is why this calculator has an optional fee field (defaulting to $0) rather than assuming one.
Applying triggers a hard credit inquiry, which typically causes a small, temporary dip in your score. Beyond that, refinancing replaces an old loan with a new one, which can shorten your average account age — also a minor, temporary factor. Making on-time payments on the new loan afterward tends to rebuild and often improve your score over time, the same as any other loan in good standing.
It depends on your own credit history and income — many lenders require a cosigner if you don't yet have an established credit profile or sufficient income on your own. Most refinance lenders offer a cosigner release option after a set number of consecutive on-time payments (commonly 12 to 36, varying by lender), but it's never automatic — you typically have to apply for release and requalify on your own credit at that point.
Yes — you're not required to refinance every loan you have. It's common to refinance only the private loans (keeping federal loans untouched to preserve their protections), or to refinance only the highest-rate loans while leaving others as-is. Each refinanced loan becomes a single new private loan with its own rate and term, so you can mix and match based on which original loans actually benefit from refinancing.
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