Estimate new monthly payments, potential savings, refinancing costs, and break-even time by comparing your existing loan terms with a proposed refinance scenario accurately.
Result = Financial inputs processed using the applicable rate, payment, compounding or cash-flow relationship shown by this calculator.The result combines the values requested by the tool, which may include price, income, rent, financing, taxes, fees, maintenance or time. An omitted recurring cost or an unrealistic growth assumption can materially change the comparison.
A Refinance Calculator provides an estimate of how refinancing an existing mortgage or loan with a new mortgage or loan can change your monthly payment, interest paid, and possible savings. You usually input your current loan balance, interest rate, remaining term, new interest rate, new term, and refinancing costs. The calculator can then compare your existing loan to the suggested refinance to determine the difference in monthly payments and time to break-even point, how much you will pay over the longer term, and the difference in costs. Use the results to compare types of refinance options before consulting lender specific loan interest rates, loan origination and other fees, borrower qualifications, taxes, and insurance.
A Refinance Calculator compares the cost of continuing your existing loan with the estimated cost of replacing it with a new loan. It calculates payments using the relevant balance, interest rate, and repayment period, then accounts for refinance costs when estimating whether and when the new loan may become less expensive.
The calculation generally evaluates two separate scenarios: the payments remaining on your current loan and the payments required under the proposed refinance. A lower interest rate can reduce the payment and interest expense, but extending the repayment term can offset some or all of that benefit.
Refinancing costs also matter. If the new loan saves $200 per month but requires $6,000 in upfront closing costs, it takes time for those monthly savings to recover the initial expense. This is commonly called the refinance break-even period.
For a standard fixed-rate amortizing loan, the monthly principal-and-interest payment can be estimated with:
M = P × [r(1 + r)n] / [(1 + r)n − 1]
Where:
When monthly payment savings are positive, a simple break-even estimate can be calculated as:
Break-even months = Upfront refinance costs ÷ Monthly payment savings
This simple break-even calculation is most useful when costs are paid upfront. If closing costs are added to the new loan balance, the new principal and monthly payment increase, so the comparison should account for the financed costs directly.
Assume a homeowner has the following mortgage and is considering refinancing.
| Input | Current Loan | Proposed Refinance |
|---|---|---|
| Loan balance | $300,000 | $300,000 |
| Interest rate | 7.00% | 6.00% |
| Remaining/new term | 25 years | 25 years |
| Refinance costs | Not applicable | $6,000 upfront |
Using the fixed-rate payment formula, the current loan's estimated monthly principal-and-interest payment is approximately $2,120.34.
The proposed refinance payment is approximately $1,932.90 per month.
Estimated monthly payment savings:
$2,120.34 − $1,932.90 = $187.44 per month
Estimated break-even period:
$6,000 ÷ $187.44 = approximately 32 months
In this example, refinancing reduces the estimated monthly principal-and-interest payment by about $187. If the homeowner pays $6,000 in refinance costs upfront and other assumptions remain unchanged, it would take roughly 32 months of payment savings to recover those costs. If the homeowner expects to sell the property or refinance again before that point, the transaction may not recover its upfront costs through monthly payment savings alone.
The new payment estimates what you would pay under the proposed refinance terms. For a mortgage, this figure may represent principal and interest only unless property taxes, homeowners insurance, mortgage insurance, or other housing costs are specifically included.
Monthly savings measure the difference between the existing loan payment and the proposed new payment. A positive number means the new scheduled payment is lower. However, a lower monthly payment does not automatically mean the refinance is cheaper overall.
The break-even period estimates how long it may take for recurring payment savings to recover upfront refinancing expenses. A shorter break-even period generally means costs are recovered sooner, but the appropriate comparison depends on how long you expect to keep the loan.
Total interest provides a longer-term comparison. A lower interest rate may reduce interest expense, while extending the loan term can increase the number of payments and potentially increase total interest even when the monthly payment falls.
One of the most important refinance comparisons is separating the effect of the interest rate from the effect of the loan term. A payment may fall because the rate is lower, because repayment is stretched over more years, or because both occur.
For example, refinancing a mortgage with 20 years remaining into a new 30-year loan may substantially reduce the monthly payment because repayment is spread across an additional 10 years. That does not necessarily produce the lowest total borrowing cost.
To make a more useful comparison, test multiple scenarios such as:
Closing costs can materially change the economics of refinancing. A refinance with an attractive interest rate may still take several years to recover its transaction costs.
Costs may be handled in different ways:
When comparing offers, use consistent assumptions. Comparing one lender's rate without fees against another lender's rate with points or credits can produce a misleading conclusion.
A cash-out refinance differs from a simple rate-and-term refinance because the new loan balance may be higher than the balance being paid off. The extra borrowed amount can increase both the monthly payment and total interest.
If you are evaluating a cash-out refinance, enter the proposed new loan amount rather than assuming the existing balance remains unchanged. A standard refinance savings comparison may not fully represent the decision because part of the new debt represents additional borrowing rather than refinancing savings.
Many refinance calculations compare principal-and-interest payments because those amounts are directly determined by the loan balance, rate, and term. Your actual monthly housing payment can also include property taxes, homeowners insurance, homeowners association charges, mortgage insurance, or other amounts.
Some of those expenses may remain similar after refinancing, while others can change. Check which components are included before comparing a calculator result with the amount currently withdrawn by your mortgage servicer.
A refinance calculation is an estimate based on the values entered. Actual refinancing terms can differ because of lender pricing, credit qualifications, property value, loan-to-value requirements, loan type, points, closing costs, prepaid expenses, escrow adjustments, insurance, taxes, and other transaction details.
The calculator also cannot determine whether refinancing is appropriate for your individual financial situation. Use the result as a scenario-comparison tool and review actual loan disclosures and lender terms before making a financial commitment.
There is no universal rate reduction that makes refinancing worthwhile. The result depends on your balance, remaining term, new term, closing costs, payment difference, and how long you expect to keep the new loan. Compare the complete scenarios rather than relying on a fixed percentage-point rule.
A simple break-even estimate divides upfront refinancing costs by monthly payment savings. For example, $5,000 of upfront costs divided by $200 of monthly savings equals approximately 25 months. More detailed comparisons may also account for financed costs and differences in principal reduction.
No. A shorter loan term, a larger new balance, cash-out borrowing, financed fees, or a higher rate can produce a higher payment. Some borrowers refinance specifically to shorten the repayment period rather than reduce the monthly payment.
Yes. A shorter-term refinance can increase the required monthly payment while reducing the number of years interest accrues. Depending on the rate, costs, and loan balance, that can reduce total interest despite the higher payment.
Yes. Closing costs affect how quickly a refinance can recover its transaction expenses and can materially change total savings. If the costs are financed, add them to the new loan balance rather than treating them only as an upfront expense.
Use the current balance or expected payoff amount required by the calculator. Do not automatically use the original mortgage amount. A lender's final payoff figure may differ slightly from a statement balance because of accrued interest or other amounts.
Start with current verified costs, then test a higher rate, a different down payment or a change in rent and ownership expenses. Compare the full scenario rather than focusing on one monthly figure.
Refinancing may be worth evaluating when the new loan changes an important part of your existing financing, such as the interest rate, monthly payment, remaining repayment period, or loan structure. The calculator is most useful when you compare several realistic scenarios instead of entering only one proposed refinance offer.
The most useful question is not simply whether the new rate is lower. Compare the new payment, refinancing costs, break-even period, payoff date, and estimated interest over the period you realistically expect to keep the loan.
Two refinance offers with similar interest rates can produce different financial outcomes because their fees, points, loan terms, and financed costs may differ. Enter each offer separately using the same current-loan information so the comparison remains consistent.
| Comparison Item | What to Check |
|---|---|
| Interest rate | Compare the stated rate for each proposed loan. |
| New loan term | Check whether the refinance resets or extends your payoff timeline. |
| Monthly payment | Compare equivalent principal-and-interest payment amounts. |
| Closing costs | Include lender fees, points, and other applicable refinance expenses. |
| Financed costs | Determine whether fees are being added to the new loan balance. |
| Break-even time | Estimate how long monthly savings take to recover upfront costs. |
| Total interest | Compare estimated interest over an equivalent holding period where possible. |
A refinance offer with the lowest monthly payment is not automatically the least expensive option. A longer term can reduce the payment while increasing the number of payments remaining.
Mortgage refinance offers may include discount points or lender credits. These features can change the tradeoff between the interest rate and the amount paid at closing.
When testing a refinance with points, include the additional upfront expense in your refinance costs. Then compare the resulting break-even period with a scenario that has fewer points and a different interest rate.
A refinance described as having no closing costs does not necessarily mean that every refinancing expense disappears. Depending on the offer, costs may be incorporated into the loan balance, offset through lender credits, or reflected in the loan's pricing.
For calculator purposes, identify how the costs are being handled. If $5,000 of expenses are added to the loan, for example, calculate the proposed payment using the increased refinance balance. If costs are offset through lender credits, compare the corresponding interest rate with alternatives that require more cash at closing.
The simple break-even calculation is useful, but it has limitations. Dividing upfront costs by monthly payment savings focuses primarily on cash flow. It may not account for differences in principal repayment, financed costs, or different payoff dates.
Consider two refinance options where one provides a substantially lower payment by restarting a 30-year term. The simple monthly break-even result may look attractive, yet the borrower may repay principal more slowly than under the existing mortgage.
For a more complete comparison, review:
A refinance generally needs enough time for its financial advantages to offset its costs. If you expect to sell the home, repay the mortgage, or refinance again relatively soon, the holding period becomes especially important.
Suppose one scenario has an estimated break-even period of 36 months. If you expect to keep the refinanced mortgage for seven years, you can evaluate several years of potential savings after break-even. If you expect to move in two years, the same transaction may not recover its upfront costs through monthly savings.
Because plans can change, consider testing multiple holding periods rather than assuming you will keep the refinance until its final scheduled payment.
Small changes in assumptions can materially affect the calculation, particularly for large mortgage balances. Scenario testing helps show how sensitive the estimated savings are to rate changes, fees, and loan terms.
Run the calculation using several plausible proposed interest rates while keeping the balance, term, and costs unchanged. This shows how much the refinance outcome depends on obtaining a particular rate.
Compare lower and higher estimated closing costs. This can show how lender fees or points affect the break-even period.
Compare different new repayment periods. A shorter term may produce a higher payment but faster principal reduction, while a longer term may reduce the required payment but extend repayment.
Consider what the refinance looks like if you keep the loan for two, five, ten, or more years rather than evaluating only the full loan term.
Answering these questions can make the Refinance Calculator result more useful when comparing real lender offers. Final loan terms, qualification, fees, escrow amounts, property-related costs, and approval decisions are determined by the lender and may differ from calculator estimates.