Refinancing almost always costs money upfront — appraisal fees, origination charges, title work — typically a few thousand dollars, even when the new rate is lower. The question isn't whether refinancing saves money each month; it's whether you'll stay in the loan long enough for those monthly savings to outweigh what you paid to get there.
That crossover point is your break-even month. Before it, you're technically still behind on the deal, even though your payment dropped. After it, every month is money back in your pocket. This calculator runs that math instantly: enter your current loan details, the new rate you're offered, and your closing costs, and it shows exactly when the trade tips in your favor.
A common rule of thumb says refinancing is worth it if you plan to stay in the home longer than the break-even period — but "common rule of thumb" isn't the same as knowing your actual number, which is what this tool is for.