Mortgage Refinance Calculator — Break-Even & Total Savings
Compare your current mortgage with a refinance. Estimate monthly savings, remaining interest, closing-cost break-even time, and total lifetime savings.
Mortgage refinance rate comparison example
Example: $300,000 balance, 25 years remaining, current rate 7.00%, new 25-year term, and $6,000 in closing costs. Values are rounded estimates.
| New rate | New monthly payment | Monthly savings | Break-even | Lifetime savings |
|---|---|---|---|---|
| 6.50% | $2,026 | $95 | 64 months | $22,415 |
| 6.00% | $1,933 | $187 | 33 months | $50,230 |
| 5.50% | $1,842 | $278 | 22 months | $77,423 |
What Is Mortgage Refinancing?
Mortgage refinancing means paying off your existing mortgage in full with a brand-new loan, then continuing your monthly payments under the new loan's rate and term. When the new rate is lower than what you're currently paying, refinancing can meaningfully reduce both your monthly payment and the total interest you'll pay over the life of the loan. However, a lower rate alone doesn't automatically make refinancing worthwhile, because taking out a new loan comes with its own closing costs — origination fees, appraisal fees, title insurance, recording fees, and other charges that can easily add up to thousands of dollars.
This calculator lets you compare your current loan against a proposed refinance side by side, showing the difference in monthly payment, remaining total interest, and total cost to payoff between the two options. It also estimates the break-even point — how many months it will take for your monthly savings to cover the closing costs you paid upfront. Because refinancing only pays off once you've stayed in the loan long enough to clear that break-even threshold, it's essential to weigh the break-even period against how long you actually expect to keep the loan or stay in the home before deciding whether refinancing makes financial sense.
How to Use the Mortgage Refinance Calculator
- Enter your current loan details Input your current loan balance, current interest rate, and the number of years remaining on your existing mortgage.
- Enter your proposed refinance details Input the new interest rate you've been quoted, the new loan term, and your estimated closing costs and fees.
- Review the side-by-side comparison Compare the monthly payment, remaining total interest, and remaining total cost for "keep current" versus "refinance" at a glance.
- Check the break-even point and lifetime impact See how many months it takes to recover your closing costs, and whether the estimated lifetime savings or extra cost makes refinancing worthwhile given how long you plan to keep the loan.
Tips for getting more out of it
- Compare the annual percentage rate and the full fee disclosure, not only the advertised interest rate. Discount points and lender credits can materially change the break-even date.
- Use the time you realistically expect to keep the property or loan. A refinance that saves money over 25 years can still lose money if you sell or refinance again before closing costs are recovered.
- Keep the new term close to the years remaining when you want a fair total-cost comparison. Resetting a 20-year balance to 30 years often lowers the payment while increasing lifetime interest.
- Run several rate and fee combinations. A slightly higher no-cost rate may beat a lower rate with expensive points when your expected holding period is short.
Mortgage Refinance Use Cases
Rates have dropped since you took out your loan
If market rates have fallen since your original mortgage closed, use this calculator to estimate how much you could realistically save in monthly payment and total cost by refinancing at today's lower rate.
Comparing offers from multiple lenders
Different lenders often quote different combinations of rate and fees. Run each offer through the calculator to compare them on equal footing rather than judging by rate alone.
Deciding whether to refinance before selling
If you're planning to sell within the next few years, check the break-even point against your expected timeline — refinancing rarely pays off if you sell the home before recouping the closing costs.
Evaluating a shorter or longer loan term
Refinancing is also an opportunity to shorten your term to pay off the loan faster and save on interest, or lengthen it to reduce your monthly payment. Compare both directions to see the full trade-off.
Mortgage Refinance Glossary
- Break-even point
- The amount of time it takes for your monthly payment savings to add up to the closing costs you paid to refinance. It's calculated roughly as closing costs divided by monthly savings. If you sell the home or refinance again before reaching this point, you won't fully recover what you spent on closing costs.
- Closing costs
- The fees charged when you take out a refinance loan, including origination fees, appraisal fees, title fees, recording fees, and other lender charges. These costs should always be weighed together with the interest rate — a lower rate with high closing costs isn't automatically the better deal.
- Amortization
- The structure of a fully amortizing loan, in which the payment amount stays the same over the life of the loan while the mix of interest and principal shifts over time — more of each payment goes toward interest early on, and more toward principal later.
- Mortgage protection insurance
- Insurance that pays off or reduces your remaining mortgage balance if you die or become disabled during the loan term. Coverage terms can change when you refinance into a new loan, so it's worth reviewing your protection, not just your rate, before switching.
- Fixed-rate vs. adjustable-rate mortgage (ARM)
- A fixed-rate mortgage keeps the same interest rate for the entire loan term, while an adjustable-rate mortgage can change periodically based on market conditions. Refinancing is also a decision about which type of future rate risk you're willing to take on.
Mortgage refinance questions
Why a lower mortgage payment does not always mean a cheaper loan
A refinance replaces the remaining balance of an existing mortgage with a new loan. The new payment depends on both the rate and the newly selected term. Lowering the rate reduces interest, but stretching the balance over more months can reduce the payment even when the borrower ultimately pays more. That is why this calculator presents monthly cash flow and lifetime cost separately.
Closing costs create a second trade-off. The simple break-even period divides upfront costs by monthly savings and estimates how long it takes for the monthly benefit to repay those costs. It is a useful first screen, but it does not include the investment return that the upfront cash might otherwise earn, tax effects, or the possibility of selling the home.
The most useful comparison keeps the same balance and tests several combinations of rate, term, and fees. If one option has a lower total cost within the time you expect to keep the loan, it may be financially attractive. The final decision should still use the lender's official disclosure because APR, escrow, mortgage insurance, and prepayment rules vary by product and country.