Wann Refinanzierung lohnt und wann Bundesdarlehen bleiben.
Refinancing student loans means replacing one or more existing loans with a new private loan at a different rate and term. The math is straightforward—lower APR and/or shorter term usually cuts total interest—but the decision is not, because federal loans carry protections that disappear when you refinance with a private lender. This guide walks through break-even, federal tradeoffs, and when the free student loan refinance calculator on Fynvorax is the right next step.
Federal protections at stake Private refinance typically ends access to income-driven repayment (IDR), Public Service Loan Forgiveness (PSLF), federal deferment and forbearance, and any pending forgiveness under federal programs. If any of those matter to your plan, do not refinance federal balances without a written comparison from a certified counselor or CPA.
How student loan refinance break-even works
Break-even on a refinance fee is the same idea as mortgage refinance: upfront cost ÷ monthly payment savings ≈ months to recover the fee. Example: $45,000 consolidated at 6.8% over 10 years might cost roughly $518/month. Refinance to 4.9% over 10 years with a $500 origination fee could land near $475/month—about $43/month saved. Break-even on the fee is roughly 500 ÷ 43 ≈ 12 months. If you will keep the loan longer than that, the fee is usually worth it—assuming you are not giving up federal benefits worth more than the interest savings.
Weighted APR and combined balances
Most borrowers have multiple loans at different rates. Your effective rate is a weighted average by balance, not a simple mean. Before you compare a lender quote, list each loan's balance and APR. The calculator accepts one consolidated balance and one current APR—use your weighted average for the current side, then enter the new offer as quoted. If you only refinance high-rate private loans and leave federal loans alone, run two scenarios: combined refinance vs private-only refinance.
When private refinance makes sense
Stable W-2 income and credit scores often in the 720+ range for best advertised rates.
No credible path to PSLF and no need for IDR because standard payments are already affordable.
Graduate PLUS or older federal rates well above current private market quotes.
You will stay in repayment long enough to clear break-even on any origination fee.
You have an emergency fund so a lower payment is optimization, not survival.
When to keep federal loans
You work or plan to work in public service and PSLF is on the table.
IDR keeps payments manageable relative to income and you may need forgiveness later.
You might need federal deferment (return to school, unemployment, medical leave).
Forgiveness or settlement discussions are active on your federal portfolio.
Your weighted federal rate is already low after pandemic-era consolidation or discounts.
Term length trap: lower payment, higher lifetime interest
Lenders often quote a lower monthly payment by stretching the term from 10 to 15 or 20 years—even when the APR drops. Total interest can rise versus keeping the original schedule. Always compare total interest paid under both loans, not just the new monthly bill. Aggressive payoff at a lower rate on the same term is the cleanest win; longer term is a cash-flow trade that may still make sense if you invest the payment difference at a higher expected return (with eyes open to risk).
Credit score, cosigner, and rate shopping
Soft-pull prequalification from multiple lenders within a 14–45 day window usually counts as one credit inquiry for scoring purposes. Compare fixed vs variable offers: variable can start lower but rises with indexes. A creditworthy cosigner may unlock rates you cannot get alone—document whether the lender offers cosigner release after on-time payments. Get the final rate disclosure in writing before you authorize payoff of old loans.
Checklist before you sign
Include origination fees in break-even, not just the rate spread.
Confirm payoff amounts and per-diem interest on the day old loans close.
Set autopay for the new loan—many lenders discount 0.25% for autopay.
Keep records of paid-off federal loans in case of servicing errors.
Re-run the calculator if you receive a windfall and might pay off early.