Refinance Break-Even Calculator

How to read your results

This calculator gives you two different numbers, and they are supposed to be able to disagree. The break-even point is a cash-flow measure: it only asks how many months of monthly savings it takes to repay the closing costs. It says nothing about whether you come out ahead over the life of the loan.

The net saving figure is the one that answers that. It compares both loans across the years you have left on your current mortgage, and crucially it counts the balance your new loan would still be carrying at that point. When the two figures point in different directions, trust the net saving.

Take the default numbers on this page: $320,000 remaining at 7.5% with 27 years left, refinanced to 6% over a fresh 30 years with $5,000 in closing costs. The monthly payment drops from $2,306.35 to $1,918.56, so you save $387.79 a month and recover the closing costs in 13 months. Multiplying that saving across the remaining 324 months suggests a gain of around $125,600 — but that ignores the fact that the new 30-year loan still owes money 27 years from now. Count that balance and the real net saving is closer to $57,600.

Why a lower monthly payment can cost you more

This is the single most common way a refinance goes wrong, and it happens because the new loan resets the schedule. A payment falls for two reasons: the rate fell, or the balance is being spread over more years. The first saves you money. The second does not — it just moves it.

The effect is dramatic late in a loan. Imagine the same $320,000 balance at 7.5%, but with only five years left instead of twenty-seven. Refinancing to 6% over 30 years cuts the payment from $6,412 to $1,919 — a saving of $4,494 a month, which recovers a $5,000 closing cost in barely two months. By the break-even measure it looks like the best decision available.

It is not. Five years in, the original loan is finished and you have paid about $64,700 in interest. The new loan still has roughly $298,000 outstanding after the same five years, and you have paid far more in total. The net saving comes out around negative $33,000. The payment fell by 70% and you ended up worse off.

The test that catches it

Before accepting any offer, compare the new term against the years you actually have left. If the new term is longer, some of your apparent saving is just deferred payment rather than real savings.

• New term shorter than or equal to your remaining years — the monthly saving is mostly genuine, and the break-even figure is trustworthy.
• New term longer than your remaining years — check the net saving, because the payment drop is partly an extension of the schedule.
• Rate barely lower and term much longer — this is the pattern that produces a great break-even and a bad deal.

How far does your rate need to drop?

The rule of thumb you will hear most often is that a refinance makes sense if your rate drops by 0.5 to 1 percentage point. It is a reasonable starting filter, but it is a poor decision rule, because it ignores the two variables that actually drive the answer: how much time is left on your loan and how much the refinance costs.

A 1-point drop early in a 30-year mortgage can pay for itself in well under two years, because you are applying the lower rate to a large balance for a long stretch of time. The same 1-point drop with six years remaining applies to a much shorter window and often never repays the closing costs, no matter how attractive the headline rate looks.

Rate alone also misses the term effect entirely. In the example above, refinancing from 7.5% to 6% over 15 years instead of 30 actually raises the monthly payment to about $2,700 — roughly $394 more than you pay now — while still cutting total interest from about $427,000 to about $166,000. That is a net saving of more than $250,000. On the rate rule it barely qualifies; on the numbers it is the strongest option on the table.

What refinancing actually costs

Closing costs on a refinance typically run 2% to 5% of the loan amount, which on a mid-size mortgage usually lands somewhere between $3,000 and $8,000. The largest single line is often the lender origination fee, followed by third-party charges such as appraisal, title insurance, credit report and recording fees. Prepaid items like escrow deposits for taxes and insurance are sometimes folded into the figure, which inflates it without being a true cost of the loan.

Ask for a Loan Estimate rather than working from a quote on a phone call. Lenders are required to issue one within three business days of an application, and the figure that matters for this calculator is the total in the closing cost section — not the monthly payment the lender leads with.

You will also see "no-closing-cost" refinances. These are almost never free. The costs are either rolled into the loan balance, where you pay interest on them for years, or absorbed in exchange for a higher interest rate. Both are legitimate choices, but neither makes the costs disappear, and both lengthen your break-even. This calculator has a control for rolling costs into the balance so you can see the difference directly.

Reasons to refinance that have nothing to do with the rate

Rate is the headline number, but it is not the only reason a refinance can be worth doing — and sometimes the best reason is not financial at all.

• Leaving an adjustable-rate mortgage. If your fixed period is ending and the rate can reset upward, refinancing to a fixed rate buys certainty. The break-even framing matters less here because the comparison is against an unknown, not a known payment.
• Removing PMI. If your home has risen in value, refinancing at a lower loan-to-value ratio can drop private mortgage insurance entirely. The monthly saving from cancelling PMI is often larger than the saving from a modest rate drop.
• Shortening the term. Moving from 25 remaining years to a 10- or 15-year loan usually raises the payment and cuts total interest enormously. Worth modelling before you assume a lower payment is the goal.
• Consolidating expensive debt. This only makes sense when the mortgage rate is materially below the rate on what you are consolidating, and it converts unsecured debt into debt secured by your home. Treat it with caution.
• Cash-out refinancing. Taking equity out changes the balance as well as the rate, which makes a like-for-like comparison impossible in this tool. Model it separately and be clear that you are trading equity for cash.

When refinancing is the wrong move

The clearest case against is planning to move soon. If you sell before the break-even point, you absorb the closing costs and none of the benefit. With a two-year break-even and a likely move in eighteen months, the arithmetic does not work regardless of how good the rate looks.

The second case is a late-in-life loan with a longer replacement term, which is the trap described above. A large payment drop late in a mortgage is almost always a term extension rather than a genuine saving.

It is also worth asking whether the cash is better used elsewhere. Paying $5,000 to save $388 a month recovers the cost in about 13 months — a guaranteed saving that is hard to beat. Paying $5,000 to save $25 a month takes more than 16 years to recover, and by then the odds are high that you have moved or refinanced again. In the second case the same $5,000 is usually better applied directly to the principal, or to a higher-interest debt you are carrying.

Finally, remember what a refinance does not fix. It will not solve an affordability problem created by taxes, insurance or HOA dues rising, because none of those change when you refinance. If your total payment has climbed because of escrow rather than interest, a new rate will not address the cause.