Mortgage refinance break-even calculator
Your refinance break-even point is the number of months it takes your monthly savings to repay your closing costs: break-even months = closing costs ÷ monthly savings. On a $300,000 loan with 20 years left at 7.5%, refinanced to 6.0% with $6,000 in closing costs, the payment drops by about $618 a month, so the break-even point is under 10 months. But if the new loan resets the clock to a fresh 30-year term, as this example does, that same refinance can add tens of thousands of dollars in interest over the life of the loan even as the monthly payment falls. The calculator below runs both numbers on your own loan.
How does mortgage refinancing work?
Refinancing pays off your current mortgage with a brand-new loan, usually to get a lower interest rate, a different monthly payment, or a different loan term. You go through much of the same process as your original mortgage: an application, a credit check, an appraisal in most cases, and a new set of closing costs. The new loan replaces the old one entirely; it does not modify or extend it. That distinction matters because the new loan also gets its own term, starting from zero, which is the source of the trade-off this page is built around.
Calculate your refinance break-even point
many lenders will also quote a custom term, like 20 or 25 years, instead of resetting to 30
| Current monthly payment (principal and interest) | $2,417 / month |
|---|---|
| New monthly payment (principal and interest) | $1,799 / month |
| Monthly savings | $618 / month |
| Break-even point | 10 months (about 0.8 years) |
| Total interest, current loan (remaining term) | $280,027 |
| Total interest, new loan (full new term) | $347,515 |
| Lifetime interest, new loan vs. current loan | $67,487 more over the life of the loan |
If you plan to keep this loan longer than about 10 months (0.8 years), the monthly savings repay the $6,000 in closing costs before then. Sell or refinance again sooner than that, and you will not recoup the cost. But resetting to a 30-year term means you would still pay $67,487 more in total interest over the life of the loan than staying on the current loan, even though the rate is lower and the payment drops. A shorter new term, or extra principal payments later, would avoid this.
Estimate. Monthly payment uses the standard mortgage amortization formula: payment = balance × r × (1+r)n ÷ ((1+r)n - 1), where r is the monthly rate (annual rate ÷ 12 ÷ 100) and n is the number of monthly payments. It covers principal and interest only, not taxes, insurance, or PMI. Your lender's actual closing costs and rate quote will differ from this estimate.
How do you calculate the refinance break-even point?
The formula is one division: break-even point (in months) = total closing costs ÷ monthly payment savings. It answers a single question: how long do you need to keep the new loan before the lower payment has paid you back for what the refinance cost to get?
Worked example, using the default numbers above: closing costs of $6,000 divided by monthly savings of $618.13 equals 9.7 months, so it takes under 10 months of the lower payment to recover the cost of refinancing. If you keep the loan at least that long, the refinance is cash-flow positive from that point on, every payment after break-even is money you would not have had at the old rate. If you sell the home or refinance again in month six, you come out behind by roughly $2,300 (the unrecovered portion of the $6,000).
Freddie Mac describes the same calculation directly: to find your break-even point, "take the total cost associated with the refinance and divide it by your monthly savings." Its guidance also flags that this simple version does not apply cleanly to a cash-out refinance or a refinance done purely to shorten your term, since those change the comparison you are making.
What closing costs should you expect when refinancing?
Freddie Mac's guidance is that refinancing typically runs 3% to 6% of your loan principal in closing costs. On a $300,000 balance, that is $9,000 to $18,000, well above the $6,000 used in the default example here; use the calculator's closing-costs field to enter your own lender's Loan Estimate once you have one. Typical line items include the loan origination fee, appraisal, title search and insurance, recording fees, and in some cases discount points paid to buy down the rate. Some lenders advertise a "no-cost" refinance; the CFPB notes this does not eliminate the cost, it moves it, either into a higher interest rate or by rolling the fees into the loan balance.
Does a lower rate always mean less interest over the life of the loan?
No. A lower rate lowers the interest charged per dollar of balance per year, but total lifetime interest also depends on how long you are paying that rate. The CFPB's own consumer guidance on refinancing states it plainly: "When you refinance to lower your interest rate, you are signing up for a new loan with a new loan term, which could be longer. That could mean a lower monthly payment, but paying more money in total." Refinancing 20 years remaining into a fresh 30-year term adds 10 years of payments, and even at a lower rate, those extra 10 years of interest can outweigh the savings from the lower rate on the original 20 years. That is exactly what happens in the default example above: the rate drops by 1.5 percentage points, the payment drops by $618 a month, and the total interest still goes up by $67,487.
Monthly savings vs. lifetime interest: how the new term changes the outcome
The table below holds the loan balance, both rates, and the closing costs fixed at the default example (a $300,000 balance, 20 years remaining at 7.5%, refinanced at 6.0%, $6,000 in costs) and changes only the new loan's term. It shows the trade-off directly: a shorter new term keeps monthly savings smaller but preserves or improves the lifetime interest picture, while a longer term maximizes monthly savings at the cost of paying more in total.
| New loan term | New payment | Monthly savings | Break-even | Total interest, new loan | Vs. current loan's remaining interest |
|---|---|---|---|---|---|
| 20 years (matches years left) | $2,149 / mo | $267 / mo | 22 months | $215,830 | $64,197 less |
| 25 years | $1,933 / mo | $484 / mo | 12 months | $279,871 | about the same ($156 less) |
| 30 years (resets the clock) | $1,799 / mo | $618 / mo | 10 months | $347,515 | $67,487 more |
Estimate. The current loan's remaining total interest at these terms is $280,027, computed with the same amortization formula as the calculator above. Matching the new term to the years actually left on the current loan (top row) captures nearly all of the rate savings; resetting to a full 30-year term (bottom row) maximizes the monthly payment drop but adds interest over the life of the loan. A custom in-between term, offered by many lenders, lands between the two.
When does refinancing make sense?
The CFPB frames this as a short checklist of situations where refinancing is less likely to pay off, worth reviewing before you apply:
- You plan to move soon. If you will sell before the break-even point, you will not recoup the closing costs.
- Your home's value has fallen. Less equity can mean fewer or worse refinancing offers.
- Your credit score has dropped. A lower score can mean a higher rate than the one advertised, shrinking or erasing the savings.
- Your current mortgage has a prepayment penalty. That penalty is a direct cost of refinancing, and it belongs in the closing-costs field of the calculator above.
Outside of those flags, refinancing tends to make sense when the break-even point is comfortably shorter than how long you expect to keep the loan, and when you have looked at the lifetime interest, not just the monthly payment, using a term that fits your actual plans rather than defaulting to whatever the lender quotes first.
The flat truth: a fast break-even does not mean a cheaper loan
Break-even math answers one question well: how long until the lower payment repays the closing costs. It does not answer a second, separate question: how much you pay in total before the loan is gone. A refinance can clear break-even in under a year and still cost you more overall, if the new term is longer than the time you had left. Before you sign, ask your lender for the payment and total interest at your current remaining term as a custom option, not only at 30 years, and compare both numbers side by side. The lower payment is real. So is the extra interest that can come with it.
Related pages: see the homeownership hub for the full picture of what owning a house costs, and the mortgage calculator for a full amortization schedule and what extra principal payments would save on either your current loan or a refinance.
Sources
- Break-even calculation ("take the total cost associated with the refinance and divide it by your monthly savings") and the 3% to 6% of loan principal closing-cost range: Freddie Mac, "Planning to Refinance".
- Refinancing to a longer term can lower the payment but raise total cost: Consumer Financial Protection Bureau, "Should I Refinance?".
- No-cost refinancing moves the cost into the rate or the loan balance rather than eliminating it: Consumer Financial Protection Bureau, "Is there such a thing as a no-cost or no-closing-cost loan or refinancing?".