Student Loan Refinance Calculator
This calculator helps you evaluate refinancing your student loan and the impact of switching between monthly and bi-weekly payment schedules. Enter your current loan details and a refinance offer to see projected payments, total interest, and an estimate of interest and time savings.
Results are produced by standard amortization formulas and common bi-weekly scheduling assumptions. The tool provides quick, conservative estimates; your lender's exact amortization table or payoff statement should be used for contractual decisions.
Side-by-side monthly amortization comparison for your existing loan and a refinance offer. Useful for estimating monthly cash flow and lifetime interest savings when both plans use monthly payments.
Inputs
Results
Current monthly payment
$325.58
Refinance monthly payment
$303.74
Total interest — current plan
$9,069.46
Total interest — refinance
$6,448.25
Estimated interest savings
$2,621.21
Term difference (months)
0
| Output | Value | Unit |
|---|---|---|
| Current monthly payment | $325.58 | USD |
| Refinance monthly payment | $303.74 | USD |
| Total interest — current plan | $9,069.46 | USD |
| Total interest — refinance | $6,448.25 | USD |
| Estimated interest savings | $2,621.21 | USD |
| Term difference (months) | 0 | months |
Visualization
Methodology
Monthly amortization uses the standard fixed-payment loan formula for periodic interest: payment = r * P / (1 - (1+r)^-n), where r is the periodic rate and n is the number of periods.
Bi-weekly projections convert the annual APR into 26 equal periods per year and compute the periodic payment for that cadence. Bi-weekly schedules typically result in 26 half-month payments per year (effectively 13 monthly payments annually), which reduces principal sooner and lowers total interest.
All numeric procedures adhere to conservative rounding and reproducibility recommendations from software and measurement guidance (see citations). Calculations assume fixed interest rates and no additional fees, prepayment penalties, or capitalization unless you input them as part of the principal.
Further resources
External guidance
Expert Q&A
Does the calculator account for lender fees or origination costs?
No. This tool does not add origination fees, closing costs, or capitalization of unpaid interest. To include fees, add them to the refinance principal field so the calculation reflects the financed total.
Are taxes, insurance, or forgiveness programs included?
No. Results exclude taxes, insurance, employer payments, and income-driven repayment or loan forgiveness programs. For public service or income-driven eligibility impacts, consult your loan servicer or official program guidance.
Why does switching to bi-weekly often save interest?
Bi-weekly schedules apply payments more frequently and typically result in one extra monthly-equivalent payment per year, so principal is reduced sooner and interest accrues on a smaller balance.
How accurate are the months-saved and interest-saved estimates?
Estimates are approximate. Months-saved uses interest-savings divided by typical monthly payment as an approximation and may differ from precise amortization schedules produced by your lender. Use lender payoff statements for exact contract figures.
Sources & citations
- NIST Software and Systems Assurance Guidance — https://www.nist.gov/publications
- ISO 9001 Quality Management Principles (for calculation controls) — https://www.iso.org/iso-9001-quality-management.html
- IEEE numerical accuracy and reproducibility best practices — https://www.ieee.org/
- OSHA guidance on risk communication (disclaimer and user safety) — https://www.osha.gov/