Refinance break-even, explained step by step

Break-even, the basic version

Refinancing costs money up front. Lender origination, appraisal, title, recording, prepaid interest, escrow setup — total closing costs run roughly 2–5% of the loan balance, or $4,000–$10,000 on a typical mortgage. You recover those costs through a lower monthly payment. Break-even months = closing costs ÷ monthly payment savings.

Example: you currently pay $2,150/month on a $350,000 balance at 7.0%. You're quoted a refi at 5.75% with $7,200 in closing costs, dropping the payment to $1,940 — savings of $210/month. Break-even = $7,200 ÷ $210 = 34 months. If you plan to stay in the house and not refi again for at least 34 months, the refi pays off. If you might sell or refi again sooner, you lose money on the transaction.

Use the actual rate sheet, not 'rates today.' Lock cost, discount points, and lender credits all move the number. A free-and-clear 'no closing cost' refi isn't free — the lender prices a higher rate to recover them. Always run break-even against the rate you would have gotten at no points, with closing costs paid out of pocket, then separately against the rolled-in option.

The amortization reset trap

Here's what break-even doesn't capture: when you refinance a 30-year mortgage that's already been amortizing for seven years into a new 30-year mortgage, you've reset the clock. Your monthly payment goes down — and you spend the next thirty years paying it instead of the twenty-three years you had left. Total interest over the life of the new loan can easily exceed the total interest you would have paid by simply keeping the old loan.

Concrete numbers: in our example, the old loan had 23 years remaining at 7.0%. If you keep it and don't refi, total remaining interest is roughly $268,000. The new 30-year at 5.75% has lower monthly interest but seven extra years of it — total interest over the life of the new loan is roughly $258,000. You save about $10,000 in total interest, not the $75,000 the monthly savings might suggest.

The fix is to refinance into a shorter term that matches your remaining payoff horizon, OR to keep the 30-year refi and accelerate payments to match the original schedule. Refinance to a 20- or 15-year if the new payment is still affordable; if not, take the 30-year for safety and make an extra principal payment of roughly $200/month to mimic a 23-year amortization. The break-even still works, but the total interest math no longer punishes you.

The 1% rule, the 2% rule, and why neither is reliable

Older personal-finance writing recommended refinancing only when the new rate was at least 1% (or, more conservatively, 2%) below the current rate. Those rules of thumb made sense in an era of $1,500 closing costs and large loan balances; they're noise now. The honest version is the break-even formula above: a 0.5% rate drop on a $700,000 loan with low closing costs can have a 22-month break-even — refinance. A 1.5% rate drop on a $120,000 loan with high closing costs can have a 60-month break-even — usually don't.

The variables that matter are: closing costs as a percentage of balance, time you expect to stay, the rate differential, and the remaining term of your existing loan. Plug all four into the calculator. Skip the rules of thumb.

When to refi even if break-even doesn't pencil

Cash-out for high-interest debt consolidation. If you're carrying $30,000 in credit card debt at 22% APR, rolling it into a mortgage at 6% saves enormous interest even if the refi 'costs' you 24 months of break-even at the new rate. Watch the term reset trap above — pay the rolled-in balance on the old credit-card-payoff schedule, not the new mortgage schedule.

Removing PMI. If you've crossed 20% equity through appreciation or principal pay-down, the lender may not automatically drop PMI. A refi removes it, and the $150–$300/month PMI elimination is independent of the rate savings — count it as additional monthly savings in the break-even calculation.

Switching from an ARM to a fixed rate before a rate adjustment that you can no longer afford. The right comparison here isn't break-even versus the current ARM rate but break-even versus the expected reset rate, which can be 2–3 percentage points higher.

Removing a co-borrower (divorce, parent off the loan). Often the only practical way is a refinance in the remaining borrower's name. Break-even math still applies but the decision is driven by the legal need, not the financial one.