Compare your current student loans with several refinance offers to find the lowest total cost and the monthly payment tradeoff.
Compare staying put with refinancing
Combine your current loans, compare two fixed-rate refinance offers, and see both the monthly-payment tradeoff and the remaining total cost.
Full comparison
| Option | Monthly payment | Term | Interest | Fees | Total remaining cost |
|---|
Estimates assume fixed rates, monthly compounding, on-time payments, and no taxes or lender credits. Current payment is the starting combined payment; it can fall when individual current loans end.
Table of contents
How to use our Student Loan Refinance Calculator
- Enter each loan in Current loans (balance $, APR %, months left) using the balance still owed, the loan APR, and the number of payments left.
- Enter each quote in Refinance offers (APR %, term months, upfront fee) so the calculator can compare all offers against the same total current balance.
- Click Calculate and read Lowest estimated remaining cost and Estimated total cost saved. Savings compare the lowest-cost option with keeping the current loans; if keeping them wins, savings are zero.
- Use the Full comparison table to compare monthly payment relief against total interest and total payments for each offer.
- Sanity-check the result: a much longer term can lower the monthly payment but may raise total interest, while a shorter term may save money but require a higher payment.
Definitions
APR: Annual percentage rate. In this calculator, APR is the yearly interest rate used to estimate monthly interest.
Months left: The number of monthly payments remaining on a current loan.
Refinance offer: A new loan quote that would pay off the current loan balances and replace them with one new payment.
Fixed monthly payment: The same scheduled payment each month for a loan with a fixed rate and fixed term.
Total cost change: Current total payments minus refinance total payments. Positive means the refinance offer costs less. Negative means it costs more.
Total interest: The extra money paid for borrowing, calculated as total payments minus the starting balance.
Balance-weighted average current APR (internal summary, not a displayed result): An average APR that gives bigger loan balances more weight than smaller balances.
Amortization: The process of paying down a loan over time with payments that cover interest and principal.
Common mistakes and quick fixes
Mistake: Combining all loans into one row in Current loans (balance $, APR %, months left) and guessing one APR.
Fix: Enter each loan separately so the current monthly payment and comparison-table interest totals use each loan's actual balance, rate and term.
Mistake: Typing years instead of months in Current loans (balance $, APR %, months left) or Refinance offers (APR %, term months, upfront fee) .
Fix: Convert years to months first. For example, 5 years is 60 months and 10 years is 120 months.
Mistake: Reading Payment change with lowest-cost option as the only decision number.
Fix: Also compare Estimated total cost saved , because a lower payment can still cost more over a longer term.
Mistake: Assuming the recommendation always selects a refinance offer.
Fix: Keeping the current loans is included in the comparison. If it has the lowest cost, it is recommended and estimated savings are zero. Compare each refinance offer's total in the table.
Mistake: Leaving an old quote in Refinance offers (APR %, term months, upfront fee) after a lender changes the rate or term.
Fix: Update the offer APR and term months before using Full comparison table to choose between quotes.
Limitations & Key Assumptions / Boundary Conditions
- The calculator assumes fixed APRs, monthly payments, and monthly compounding for both current loans and refinance offers.
- Entered origination fees are included as upfront costs. Lender credits, late fees, autopay discounts, variable-rate changes, taxes, and cash incentives are not included.
- It assumes each refinance offer pays off the full current loan balance on the same day and starts a new fixed payment schedule.
- Current loans are calculated separately by balance, APR, and months left. The current starting monthly payment may drop later if one loan ends before the others.
- Federal loan protections, income-driven repayment, forgiveness options, deferment, and forbearance are not priced into the dollar results.
- APR values of 0% are allowed. Negative APRs, zero balances, and terms outside 1 to 600 whole months are not valid inputs.
Methodology
How the math works
Each current loan is calculated on its own, then the results are added. Each refinance offer is calculated on the total current balance, because the new loan replaces the old loans.
monthly_rate = apr_percent / 100 / 12
payment = balance * monthly_rate / (1 - (1 + monthly_rate)^(-months))
if monthly_rate = 0, payment = balance / months
current_total_interest = add(payment_i * months_left_i - balance_i)
current_total_paid = add(payment_i * months_left_i)
offer_total_paid = offer_payment * offer_term_months + upfront_fee
cost_change = current_total_paid - offer_total_paid
weighted_average_current_apr = add(balance_i * apr_i) / add(balance_i)
How offers are ranked
The lowest-cost option is whichever has the smallest total payments, including keeping the current loans. Upfront refinance fees are included in the offer totals. If two offers have the same total payments, the calculator picks the one with the lower monthly payment. If those are still tied, it picks the shorter term.
Mini example
Suppose the current loans are $12,000 at 6% APR for 60 months and $8,000 at 5% APR for 48 months. The current starting monthly payment is about $416.23, and the current total interest is about $2,762.87. A refinance offer of 4% APR for 60 months on the $20,000 total balance has a monthly payment of about $368.33 and total interest of about $2,099.83. The total cost change is $2,762.87 minus $2,099.83, or about $663.04 saved.
Calculation notes
Dollar results are rounded for display, but the comparison uses the calculated payment values before display rounding. A positive cost change means the refinance offer has lower total payments than the current loans. A negative cost change means it has higher total payments.