Mortgage refinance break-even: the calculation that decides it

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Refinancing replaces your existing mortgage with a new one. If the new rate is lower, your payment falls. But arranging the new loan costs money up front, and until the accumulated monthly savings have repaid that cost, you are behind. The month you catch up is the break-even point, and it is the number the decision turns on.

The basic calculation

Divide your total closing costs by your monthly saving.

$6,000 of closing costs ÷ $250 saved per month = 24 months to break even.

Then ask one question: will I still have this mortgage in 24 months? If you might sell, move or refinance again before then, the refinance loses money. If you are confident you will be there for five or ten more years, it is straightforwardly worth doing.

The calculation is simple. The mistakes come from getting the inputs wrong.

What counts as a closing cost

Use the total, not just the lender's fee. Depending on where you are and what loan you take, that can include the lender's origination charge, any discount points you buy, appraisal or valuation fees, title search and title insurance, recording or registration fees, credit report fees, and prepaid items such as escrow deposits.

Two rules keep this honest. First, if a cost is rolled into the loan balance rather than paid at closing, it still counts — you are borrowing it and paying interest on it. Second, get the standardised Loan Estimate from every lender you approach and compare the itemised fee page, not the summary. That page is where the differences between lenders actually appear.

The term reset nobody mentions

Here is the part that turns apparent savings into a real loss.

If you are eight years into a 30-year mortgage and you refinance into a new 30-year mortgage, your payment drops for two reasons: the lower rate, and the fact that you have just stretched the remaining balance back over a full 30 years. You have added eight years of payments. Even at a lower rate, the total interest over the life of the loan can be higher than if you had done nothing.

The fix is to refinance into a term that matches your remaining schedule, or shorter. If you have 22 years left, look at a 20-year or 15-year loan. The payment saving will be smaller or may vanish entirely, but the total interest saving is real, and that is what you were trying to achieve.

Two numbers, not one

Judge every refinance on both the break-even month and the change in total interest over the remaining life of the loan. A refinance that improves one and worsens the other is a cash-flow decision, not a saving — which is a legitimate reason to do it, as long as you know that is what you are choosing.

A worked example

You have $280,000 remaining on a 30-year mortgage at 6.9%, with 24 years to go. Principal and interest come to roughly $1,930 a month. A lender offers 5.75%.

New 30-year loan. Payment falls to about $1,634. You save $296 a month. With $7,000 of closing costs, you break even in about 24 months. But you have restored the term to 30 years, adding six years of payments and increasing total interest paid.
New 20-year loan. Payment is about $1,966 — slightly higher than now. There is no monthly saving to break even against, but you finish four years sooner and cut total interest substantially.
New 24-year loan, matching what remains. Payment about $1,800, saving $130 a month. Break-even is around 54 months, and the total interest genuinely falls because the term has not been extended.

All three are the same rate from the same lender. Which one is right depends on whether you need the monthly cash flow or the lower lifetime cost. Nobody can answer that for you, but you should know which one you are buying.

So-called no-cost refinancing

Some lenders advertise refinancing with no closing costs. The costs have not disappeared; they have been moved. Either they are added to your loan balance, so you borrow and pay interest on them, or the lender gives you a credit in exchange for a higher rate than you would otherwise get.

That trade can be reasonable if you expect to move within a few years, because you avoid paying up front for a benefit you will not hold long enough to realise. Over a long hold, it is more expensive. Ask the lender for the same loan quoted both ways — with costs paid and with costs absorbed — and compare the two directly.

When refinancing is not about rate

Several good reasons to refinance have nothing to do with lowering your rate. Removing mortgage insurance once you have enough equity can save more than a rate cut. Moving from an adjustable to a fixed rate buys certainty ahead of a reset. Removing a former partner from the loan after a separation may require a refinance regardless of pricing.

Cash-out refinancing, where you borrow more than you owe and take the difference, deserves particular caution. You are converting home equity into spendable money and securing that new borrowing against your home. For a value-adding renovation that can be sensible. For consumption, or to clear unsecured debt, you are trading a debt that cannot cost you your house for one that can.

Questions people ask

How much of a rate drop makes refinancing worthwhile?

There is no universal threshold, despite the rules of thumb you will read. A small drop on a large balance with low fees can beat a large drop on a small balance with high fees. Run the break-even calculation with your own numbers rather than relying on a percentage rule.

Does applying to several lenders hurt my credit?

Mortgage enquiries made within a focused shopping window are generally treated as a single event by credit scoring models. The cost of not shopping around is far greater than the small scoring impact.

Can I refinance if my home has lost value?

It is harder, because lenders care about the loan-to-value ratio. Some programmes exist for borrowers with limited or negative equity. Speak to your current servicer first, since they may have options a new lender cannot offer.

How long does refinancing take?

Commonly a month or more from application to closing, depending on appraisal scheduling and how quickly documentation is provided. Rate locks have expiry dates, so ask what the lock period is and what happens if closing runs past it.

Your refinance has a break-even month. Find it before you sign.