Estimate how much refinancing your student loans could save — free, private, no email required.
Student loan refinancing replaces one or more existing loans with a single new private loan, ideally at a lower interest rate, a different term, or both. This tool compares the total interest you'd pay under your current loan terms against an estimated new refinance rate and term, using standard amortization math — the same method lenders use to calculate a fixed monthly payment that fully pays off a balance over a set number of years.
It shows both the estimated monthly payment change and the total interest saved (or added) over the life of the loan. That distinction matters more than it sounds: a lower rate can save significant money, but a longer new term can quietly increase total interest paid even when the new rate is lower than your current one. This calculator shows both effects side by side so you can see the real tradeoff, not just the headline rate a lender advertises.
Everything runs locally in your browser. Nothing you type here is transmitted to a server, stored, or shared — you can close the tab and the numbers are gone. That also means the calculator can't save your results between visits, so it's worth writing down or screenshotting anything you want to compare later.
Current total loan balance is the principal you still owe today, not the original amount you borrowed. If you have several loans you're considering refinancing together, add up their current balances. A refinance lender will do the same thing when it pays off your old loans and issues one new one.
Current interest rate should be the actual rate on your existing loan (or a balance-weighted average if you're combining multiple loans with different rates). Getting this number wrong in either direction will distort your savings estimate, since interest compounds against the balance every month.
Current remaining term is how many years are left on your current repayment schedule — not the original term you started with. If you're seven years into a 10-year loan, enter 3, not 10. This is one of the most common input mistakes people make when running a refinance estimate for the first time.
Estimated new refinance rate is the rate you expect a new lender might offer. Since this calculator doesn't pull live rate feeds from any lender, this should be a rate you've actually been quoted, or a conservative estimate based on current advertised ranges you've researched directly with lenders. Treat any number you haven't confirmed with a real lender as a placeholder for planning purposes only.
New loan term is the repayment period on the refinanced loan. This is the input people change the least carefully, even though it has an outsized effect on total interest — see the worked example below.
Using the calculator's own sample numbers above — a $35,000 balance, a current rate of 6.8% with 10 years remaining, refinanced into a new rate of 4.5% — here's what the amortization math actually produces:
Refinancing into the same 10-year term: the estimated monthly payment drops from about $403 to about $363, a savings of roughly $40 a month. Because the term didn't change, that lower rate also lowers total interest paid over the life of the loan, from an estimated $13,334 down to about $8,528 — a lifetime interest savings of roughly $4,806. In this case, both the monthly payment and the total cost improve.
Refinancing into a longer 15-year term at the same 4.5% rate: the estimated monthly payment falls much further, to around $268 a month — a payment drop of about $135. That feels like the better deal every month. But because you're now paying interest for five extra years, the estimated total interest paid barely moves, landing around $13,195 — almost identical to the $13,334 you'd pay by not refinancing at all. The lower rate is nearly canceled out entirely by the longer runway.
Neither outcome is automatically wrong. A lower monthly payment can be exactly what someone needs during a tight financial stretch. The point is that "lower payment" and "lower total cost" are two different questions, and a refinance offer can answer one without answering the other. Always check both numbers in the result table above before deciding a lower payment means you're saving money overall.
Comparing only the monthly payment. As the example above shows, a lower payment achieved by stretching the term can leave you paying about the same — or more — in total interest. Always compare total interest and total amount paid, not just the monthly number.
Using the original loan term instead of the remaining term. If you're several years into repayment, entering your original term overstates how much interest you have left to pay under your current loan, which understates your real refinancing benefit or cost.
Assuming a lower advertised rate applies to you. Refinance lenders advertise a range of rates; the rate you actually qualify for depends on your credit history, income, and the lender's underwriting, and can be meaningfully higher than the lowest advertised figure. Confirm your real, personalized rate directly with a lender before treating any number as final.
Forgetting that fixed and variable rates behave differently. A variable rate can start lower than a fixed rate but move upward over the life of the loan. If a lender quotes you a variable rate, ask what the rate could realistically become and re-run this calculator with that higher figure as a stress test.
Refinancing federal loans without weighing what you'd give up. This is the single highest-stakes mistake in this category, and it deserves its own explanation — see the warning below and our full comparison guide.
If any part of your balance is a federal student loan, refinancing it with a private lender is a one-way door. Once a federal loan is paid off and replaced by a private loan, it permanently loses access to federal protections, including income-driven repayment plans, federal deferment and forbearance options, and federal forgiveness programs such as Public Service Loan Forgiveness. A private lender is not required to offer any equivalent replacement for these protections, and most don't.
This calculator has no way of knowing your income stability, career path, or whether you might need one of those protections in the future — it only compares interest math. Before refinancing any federal loan, read our full Refinancing vs. Keeping Federal Loans guide, and confirm your current loan type, servicer, and any protections you currently qualify for directly at studentaid.gov or with your loan servicer before making a final decision.
These pages go deeper into the decisions this calculator can't make for you — whether refinancing makes sense given your loan type and career situation, and how the numbers above were actually calculated.