Student Loan Refinance Calculator
Refinancing swaps your current student loan for a new one at a lower rate. The saving depends on the rate gap and the new term. This calculator compares both side by side — the new monthly payment, the monthly saving and the total interest you keep.
Use this student loan refinance calculator to see whether a new rate is worth it. Enter your current balance, rate and remaining term, then the new rate and term you are offered — it compares the two loans and shows the new payment, the change in your monthly cost, and how much total interest you would save or lose.
Enter your current loan and the new offer, then press Calculate to compare.
How the student loan refinance calculator works
Refinancing is only worth it if the numbers say so, and this calculator settles the question by modelling both loans. It amortizes your current loan — the balance at your current rate over the remaining term — to find your present payment and total remaining interest. Then it amortizes the same balance at the new rate and term to give the refinanced payment and its total interest. Side by side, you see the change in your monthly payment and, crucially, the difference in total interest — the real measure of whether the refinance pays off.
The saving comes from the rate, but the term is just as important. Dropping from a high rate to a lower one cuts interest sharply; stretching the term to lower the payment can quietly give some of that back. This tool makes the trade‑off visible so you can pick a term that saves interest, not just lowers the payment. If instead you want to keep your loans and simply finish sooner, compare with the student loan payoff calculator.
How the comparison is built
- Monthly change — new payment vs current payment
- Total interest — payment × months − balance, each loan
- Saving — can be negative if the new term is long
The federal loan warning
Before refinancing, understand what you may give up. Refinancing federal student loans into a private loan permanently forfeits federal protections — income‑driven repayment plans, generous deferment and forbearance, and any loan forgiveness you might qualify for. Those safety nets can matter enormously if your income drops. For that reason, refinancing usually makes the most sense for private loans, or for financially stable borrowers with secure incomes who are confident they will not need federal options. If there is real doubt, a lower rate is rarely worth losing those protections.
Shop the rate, mind the term
Refinance rates depend heavily on your credit and income, so it pays to get quotes from several lenders — most check your rate with a soft inquiry that does not affect your score. When you compare offers, look past the monthly payment to the total interest and the term. The lowest payment often comes with the longest term and the highest lifetime cost. Reputable student loan refinancers charge no fees, so the whole benefit is in the rate and term you choose here.
What you give up by refinancing federal student loans
This is the decision that matters most, and it is easy to underestimate. Refinancing moves your loans to a private lender, so any federal loans you refinance permanently lose their federal protections — and you cannot undo it. You give up income-driven repayment (payments tied to your income), federal deferment and forbearance if you hit hard times, and every forgiveness program, including Public Service Loan Forgiveness for nonprofit and government workers and Teacher Loan Forgiveness. If there is any chance you will need those — you work in public service, your income is unstable, or you are pursuing forgiveness — keeping federal loans is usually the safer choice even at a slightly higher rate. Refinancing shines for private loans, which have none of these protections to lose, and for financially stable borrowers with strong credit who simply want a lower rate.
Estimate only — not financial advice. Refinancing federal loans forfeits federal benefits. Rates depend on credit and income; confirm terms with the lender before proceeding.
How to use it & key terms
Enter your current balance, current rate and remaining term, then the new rate and term you are offered, and press Calculate to compare payment, term and total interest.
| Term | What it means |
|---|---|
| Refinance | Replacing existing loans with a new private loan at a new rate. |
| Current rate | The weighted average rate on your existing loans. |
| New term | Length of the refinanced loan. |
| Monthly change | How much lower (or higher) the new payment is. |
| Interest saved | Current total interest minus the new loan's. |
| Federal benefits | Protections lost when refinancing federal loans privately. |
Sources & methodology
The calculator amortizes your current balance at the current rate over the remaining term using the standard fixed‑rate formula, giving your current payment and total interest (payment times months minus the balance). It then amortizes the same balance at the new rate over the new term for the refinanced payment and its total interest, and compares the two — the monthly change and the interest saved or lost. It assumes the full balance is refinanced with no fees, which reflects how most no‑fee student loan refinancers operate; any lender fee would reduce the saving.
Sources: Standard fixed‑rate loan amortization formula; federal student loan benefit trade-offs per U.S. Department of Education guidance on refinancing into private loans.
Fixed vs variable, cosigners, and partial refinancing
Once you have decided refinancing is on the table, several choices shape whether it actually helps — and they sit apart from the well-known warning about giving up federal protections.
The first is fixed versus variable rate. A fixed rate never changes, so your payment is predictable for the whole term. A variable rate usually starts lower but rises and falls with the market, which can save money if you plan to repay quickly but becomes a gamble over a long payoff, where a few rate increases can erase the initial advantage. As a rough guide, a variable rate suits a short, aggressive payoff; a fixed rate suits anyone who values certainty or expects to carry the loan for years.
The second is the cosigner question. A borrower with limited credit history often needs a cosigner to qualify or to reach the best rate — but that person is fully on the hook if payments are missed. Look for a lender that offers cosigner release, which lets you remove the cosigner after a stretch of on-time payments and proof you can carry the loan alone. It turns a temporary helping hand into exactly that, rather than a permanent obligation for a family member. The third, and most underused, is that refinancing is not all-or-nothing: you can refinance selectively, moving only your high-rate private loans into a new loan while leaving federal loans untouched to preserve their income-driven repayment, forgiveness and forbearance options.
Qualifying comes down to the familiar trio lenders weigh:
- Credit and income — a solid score and steady earnings unlock the lowest advertised rates; weaker files are quoted higher.
- Term length — a shorter term saves interest but raises the payment, so pick the shortest one you can comfortably sustain.
The mechanics are simple: a new lender pays off the old balances and you make one payment going forward. But a lower headline rate stretched over a longer term can still cost more overall, so use the calculator above to compare the new payment and the total interest before committing — and reserve refinancing for situations where you keep, or knowingly weigh, the protections you would lose.
Frequently asked questions
How does refinancing a student loan work?
Refinancing replaces one or more existing student loans with a single new private loan, ideally at a lower interest rate. A new lender pays off the old balances, and you make one payment on the new loan at the new rate and term. A lower rate reduces interest; a shorter term saves more but raises the payment.
Will refinancing save me money?
It saves money when the new rate is meaningfully lower than your current rate and you do not stretch the term too far. A lower rate cuts total interest, but extending the term can offset that even at a lower rate. This calculator shows the new payment and the total interest both ways so you can see the real saving.
Should I refinance federal student loans?
Be careful. Refinancing federal loans into a private loan gives up federal protections — income-driven repayment, deferment, forbearance and forgiveness programs. If you may need those, keeping federal loans is often wiser even at a slightly higher rate. Refinancing usually makes the most sense for high-rate private loans or stable borrowers who won't need federal options.
Does a longer term lower my payment but cost more?
Often yes. A longer refinance term lowers the monthly payment but can increase total interest, even at a lower rate, because you pay for more years. If your goal is to save the most interest, choose the shortest term whose payment you can comfortably afford.
What credit score do I need to refinance student loans?
Private refinance lenders typically look for good to excellent credit, often a score in the high 600s or above, along with steady income and a manageable debt-to-income ratio. A stronger profile earns a lower rate. Borrowers with thin credit sometimes refinance with a creditworthy cosigner to qualify or improve the rate.
Are there fees to refinance a student loan?
Most reputable student loan refinance lenders charge no application, origination or prepayment fees, which is a key difference from mortgage refinancing. Always confirm there are no fees before proceeding, since any fee would reduce the savings. The main cost of refinancing federal loans is the loss of federal benefits, not a dollar fee.
Can you refinance student loans with a cosigner?
Yes, and it is a common way to qualify or get a better rate. If your credit or income is thin — often the case soon after graduation — a creditworthy cosigner reduces the lender's risk and can unlock a materially lower rate. Many lenders also offer cosigner release after a set number of on-time payments, which frees your cosigner once you have proven the loan is affordable on your own.
When should medical residents refinance student loans?
Timing is everything for residents. During residency your income is low, so many borrowers wait or use lender programs that allow token payments of around $100 a month until training ends. Refinancing during residency locks in a rate but converts federal loans to private and forfeits Public Service Loan Forgiveness, which matters because many residents train at nonprofit hospitals that qualify. A common approach is to keep federal loans through residency, then refinance once your attending income and credit are strong.
How much student loan debt is worth refinancing?
Refinancing pays off more the larger your balance, because the saving comes from a lower rate applied to what you owe. On a big balance of $50,000 or $100,000 and up, even a small rate drop can save thousands over the life of the loan, while on a few thousand dollars you usually need a much larger rate gap to make switching worthwhile. There is no legal minimum, though many lenders want at least $5,000 to $10,000. Weigh the monthly saving against any federal protections you would give up, and consider refinancing only the private-loan portion if you want to keep federal options open.