Refinancing replaces your existing mortgage with a new one. People do it to lower a rate, to change a term, to escape mortgage insurance, or to pull equity out as cash. All four are legitimate, and all four are routinely done at the wrong moment because the decision gets made on the headline rate rather than on the arithmetic.
The good news is that the core calculation is simple. The complications are in what the simple calculation leaves out.
Start with break-even
A refinance is a purchase. You pay closing costs now to buy a lower payment later, and the question is how long until the purchase pays for itself.
Break-even months = total refinance costs ÷ monthly payment saving
If refinancing costs $6,000 and saves $200 a month, you break even at 30 months. Stay past that and you're ahead; sell or refinance again before it and you've lost money.
Refinance closing costs cover much of what you paid the first time — origination, appraisal, title, recording, prepaids. They are not trivial, and the single most common error is assuming a "no-cost" refinance is free. It isn't; the costs are folded into the loan balance or paid for with a higher rate. Either way you pay, just less visibly.
Why the "1% rule" is unreliable
The old guidance — refinance when rates drop a full percentage point — is a rule of thumb from an era of more uniform loan sizes, and it ignores the two variables that actually decide the outcome.
Loan size. A given rate drop produces a much larger monthly saving on a large balance than a small one. On a big loan, a modest rate improvement clears break-even quickly. On a small loan, even a substantial drop may never justify the fixed closing costs.
Time remaining. Refinancing with 25 years left is a completely different proposition from refinancing with 8 years left, because most of the interest on the old loan has already been paid.
Ignore the rule and run your own numbers. It takes five minutes with a calculator: work out the payment on your current balance at your current rate and remaining term, then at the new rate and new term, and take the difference.
The term-reset trap
This is the one that quietly costs people the most, and it rarely appears in the pitch.
Suppose you're seven years into a 30-year mortgage and refinance into a new 30-year loan at a lower rate. Your monthly payment drops, which feels like a clear win. But you have just extended your repayment from 23 remaining years to 30 — you've added seven years of payments.
Worse, amortization restarts. Those seven years of gradually shifting your payment toward principal are undone; you're back at the front of the schedule where most of each payment is interest. It is entirely possible to lower your rate, lower your payment, and still pay more total interest over the life of the loan.
Two ways to avoid it. Refinance into a term matching what you have left, if the lender offers it. Or take the 30-year loan for the payment flexibility, but keep paying the old higher amount — the extra goes to principal and you retire the loan on roughly the original schedule while retaining the option to pay less in a bad month. Our guide on paying off your mortgage early covers how to make sure that extra actually lands on principal.
The honest comparison is never payment-versus-payment. It's total remaining cost of staying put versus total remaining cost of refinancing, including the closing costs.
Rate-and-term vs cash-out
A rate-and-term refinance changes the rate, the term, or both, and the balance stays roughly the same. This is the standard case, and it generally carries the best pricing.
A cash-out refinance replaces your mortgage with a larger one and hands you the difference. Lenders treat it as higher risk, so expect stricter equity requirements and typically less favourable pricing than an equivalent rate-and-term refinance.
Cash-out is genuinely useful for consolidating expensive debt or funding work that adds real value. It is a poor way to fund consumption, for one specific reason: you are converting unsecured or short-term borrowing into debt secured against your home and stretched over decades. A credit card balance moved into a 30-year mortgage costs less per month and often more in total — and now your house is the collateral.
Good reasons that aren't about rate
- Escaping FHA mortgage insurance. On most modern FHA loans the insurance premium lasts the life of the loan. Refinancing into a conventional loan once you have equity is the standard exit — see when does PMI go away. The saving here is the premium, not the rate.
- Leaving an adjustable-rate loan. Moving to a fixed rate before an adjustment period buys certainty, which has value even if the headline rate isn't lower.
- Shortening the term deliberately. Moving from 30 years to 15 usually raises the payment but cuts total interest substantially.
- Removing someone from the loan. After a divorce or a change in circumstances, refinancing is generally the only way to release a borrower from the obligation.
What can go wrong
Refinancing is a full mortgage application, not an administrative update. Your credit, income, and the property are all reassessed at today's standards.
- The appraisal comes in low. Less equity than expected can change your pricing, trigger mortgage insurance, or sink the application.
- Your income changed. Becoming self-employed since the original loan often means significantly more documentation.
- Your credit slipped. Pricing tiers are unforgiving; a lower score can erase the benefit.
- You don't hold long enough. The most common failure of all — refinancing, then moving before break-even.
A sane process
- Find your current balance, rate, and months remaining. Everything depends on these three.
- Get quotes from several lenders in a compact window so credit inquiries count once.
- Compare Loan Estimates side by side — they're standardised for exactly this.
- Compute break-even honestly, including costs rolled into the balance.
- Compare total remaining cost, not just monthly payment, and match the term where you can.
- Ask how long you'll realistically keep this loan. If the answer is shorter than break-even, stop.
The bottom line
Refinancing pays when you'll hold the new loan well past its break-even point, and when the comparison is made on total remaining cost rather than on the monthly payment. Ignore the 1% rule; your loan size and remaining term matter more than the size of the rate drop.
Watch the term reset above everything else — a lower payment achieved by restarting a 30-year clock is frequently a worse deal wearing a better outfit. And treat cash-out as a serious decision about secured borrowing, not as a convenient source of money.