Break-even guide
The useful answer includes fees and the debt still owed, not only a smaller payment.
At each month, compare payments made plus remaining balance on the current loan with upfront costs, refinance payments, and remaining refinance balance. The first month the refinance is ahead is break-even. This is a net financial position, not cash left in a checking account.
Short stay: A homeowner with a $410,000 balance, 27 years left at 7.25%, and $7,800 in costs may see a lower payment at 5.95%. If they sell in 18 months before recovery, the refinance can still lose money.
Longer stay: The same hypothetical homeowner who keeps the loan for five years has more time for the lower rate to offset fees. Run both cases with your payoff statement; the numbers are examples, not a quote.
Refi Reckoner models fixed principal-and-interest payments. Taxes, insurance, changing home value, lender credits, rate locks, and program rules can change a real result. A lower payment does not always mean lower cost: a new 30-year term may extend repayment.
What number should I use? Use the servicer payoff balance and lender Loan Estimate. What if I move first? Compare at your expected move month, not at year 30.
Use the calculator to find your actual break-even month and compare the balance at your expected exit date.