Refinancing replaces your current mortgage with a new one, usually to get a lower rate. It can save real money — but only if the savings outrun the closing costs, and only if you do not quietly stretch the loan back out to its full length.
TL;DR — Enter your current loan and the new one in the refinance calculator to see the monthly saving and the break-even month.
The break-even point
Refinancing is not free — expect closing costs of a few thousand dollars. The key question is how long it takes the lower payment to pay those costs back. If your new payment is $250 lower and closing costs are $5,000, you break even in 20 months. Stay past that and you are ahead; sell or refinance again before it, and you lost money on the deal.
The lower-payment trap
Here is the catch most refinance pitches skip: if you are ten years into a 30-year mortgage and refinance into a new 30-year loan, the payment drops partly because you just added ten years back. You might pay more total interest even at a lower rate. The fix is to compare lifetime interest — the calculator shows the remaining interest on your current loan against the new loan’s total, so you see the real trade-off.
When it usually makes sense
Refinancing tends to pay off when the rate drop is meaningful (often cited as around 0.75% or more), you will stay in the home well past break-even, and you keep the term similar or shorter. Run your own numbers in the refinance calculator — these are estimates for planning, not a loan quote.