Mortgage Refinance Calculator
Thinking of refinancing? Enter your current loan and the new rate, term and closing costs, and this tool shows your new monthly payment, your monthly saving, and the break-even point — the moment the saving finally pays back the fees. It works in any currency.
The one number that decides it: break-even
A refinance almost always comes with closing costs, so a lower rate only helps if you keep the loan long enough to recover those fees. The break-even point — closing costs divided by your monthly saving — is the honest test. Stay in the home past it and the refinance genuinely saves you money; sell or move before it and you've paid fees for nothing. The calculator puts that number front and centre.
Worked example
On a $300,000 balance with 28 years left at 7%, your payment is about $2,039. Refinance to 5.5% over 30 years with $5,000 in closing costs and the new payment drops to about $1,703 — a $335 monthly saving that breaks even in roughly 15 months. Because the term restarts at 30 years, watch the total-interest figure too. Enter your own loan above.
Watch the term, not just the rate
- Restarting the clock lowers the monthly payment but can raise lifetime interest, even at a lower rate, because you pay for longer.
- To capture the rate cut without the term penalty, refinance to a shorter term (say 15 or 20 years) or keep paying your old amount — you'll clear the loan sooner and pay far less interest.
- Rolling costs into the loan pushes the break-even further out; paying them upfront gives the fastest payback.
Methodology & assumptions
Both payments use the standard amortization formula on the current balance at each rate and term. Break-even = closing costs ÷ monthly saving. Interest figures are payment × months − balance for each loan. It assumes you refinance the existing balance, pay closing costs upfront, and hold each loan to term; it ignores taxes, insurance, PMI and cash-out. Treat it as a planning estimate, not a lender quote. See our methodology and editorial policy.
Frequently Asked Questions
How do I know if refinancing is worth it?
Compare the break-even months to how long you'll stay. Past break-even, you save; before it, the fees win.
Why might a lower rate still cost more overall?
Because restarting a 30-year term means paying interest for longer. The interest comparison above shows this; a shorter term fixes it.
Should I roll in the closing costs?
It's convenient but adds to the balance and delays break-even. Paying upfront recovers the cost fastest.
See the full payment breakdown
Check exactly how each payment splits between principal and interest over the life of the new loan.
Open the amortization calculator →Related calculators
Sources
Uses the standard mortgage amortization formula and the closing-cost break-even method. Figures are estimates for planning, not a lender quote — confirm rate, term and fees with a lender. See our methodology and editorial policy.