Loan Refinance Calculator

Assumptions & Limitations

The calculator assumes the full remaining balance is refinanced into a new fixed-rate loan with monthly payments and interest compounded monthly — the norm for most personal loans, auto loans, and mortgages in the United States. It does not include origination fees, closing costs, prepayment penalties, taxes, insurance, or other charges. Real refinance offers may carry these costs, so factor them in separately when weighing a deal.

The remaining payoff of the current loan is simulated from its balance, payment, and APR. If the payment does not cover the monthly interest, the balance would never be repaid and the loans cannot be compared. The current loan must amortize within 1,200 months on the website; spreadsheet downloads use a 600-month limit so the workbook remains bounded. Proposed terms are rounded to the nearest whole month on both surfaces.

Calculator Inputs

You only need to enter what you already know about each loan.

• Remaining balance: How much you still owe on the current loan today, not the original amount borrowed.
• Monthly payment: The fixed amount you currently pay each month. It is used with the balance and APR to simulate how many payments remain.
• Current APR: The current loan’s annual percentage rate. If you only know the interest rate, it is a close substitute for a fee-free loan. Learn about origination fees.
• New loan term: The proposed repayment period in years or months. A shorter term usually means a higher monthly payment but less interest overall; a longer term does the reverse.
• New APR: The annual percentage rate offered, or expected to be offered, on the proposed refinance. A lower APR is the main lever that makes refinancing pay off.

Understanding Your Results

The summary at the top shows how your monthly payment and total remaining cost change. Beneath it, the table compares the two loans side by side:

• Loan amount: The balance being repaid. Because the refinance replaces what you owe, this is the same for both loans.
• Loan term: The number of payments left on the current loan versus the full rounded term of the proposed loan.
• Monthly payment: The regular amount paid each month under each loan.
• Interest rate: The APR of each loan.
• Total interest: The interest paid over the remaining life of each loan.
• Total payments: Everything left to pay — the balance plus all remaining interest.

The current-loan total comes from the simulated payoff rather than the regular payment multiplied by a rounded term. That means a smaller final payment is counted correctly.

Is Refinancing Worth It?

Because the balance stays the same, a refinance comes down to two questions: does your monthly payment go down, and does your total remaining cost go down? That creates four situations — and a lower monthly payment is not automatically a win:

• Lower payment and lower total cost: The straightforward win — you pay less each month and less over the remaining life of the loan.
• Higher payment but lower total cost: Often the best financial move, usually driven by a lower rate or shorter term. You pay more each month but save meaningfully overall, so it may be worthwhile if the higher payment comfortably fits your budget.
• Lower payment but higher total cost: A trade-off, usually from extending the term. It can ease a tight budget, but you pay more in the long run, so go in with eyes open.
• Higher payment and higher total cost: No upside — the proposed terms cost more on both measures.

The verdict shown with your results highlights which of these situations applies to the numbers you entered.