Direct answer
A mortgage refinance is economically ahead only after cumulative comparable savings recover all switching costs, and only if the loan remains in place long enough without a term extension erasing the gain.
What this calculation tells you
The model compares entered existing and replacement mortgage paths and identifies a cash-flow break-even.
It cannot predict valuation, approval, future rates, taxes, or how long the borrower keeps the loan.
Where it is used
Homeowners
Screen a refinance quote.
Mortgage advice
Make fees and horizon explicit.
Cash-flow planning
Separate lower payment from total saving.
Equity planning
Show costs financed into the balance.
Common situations
- Rates are lower than the current mortgage.
- A shorter or longer term is proposed.
- Costs will be financed.
- The property may be sold soon.
Use today's existing-loan baseline
Capture payoff balance, remaining term, rate structure, penalties, and expected payments rather than restarting the original mortgage illustration.
Include every switching cost
Valuation, legal, title, lender, government, broker, exit, and financed costs should be entered where applicable and current.
Measure through the expected exit
Compare balances and cumulative costs at the likely sale, payoff, or next refinance date—not only at each loan's different maturity.
Common mistakes
Before relying on mortgage refinancing and the real break-even point, test the stated assumptions and keep its decision boundary visible.
- Comparing advertised rates only.
- Ignoring financed fees and reset term.
- Assuming the mortgage remains until break-even.
Practical questions
Frequently asked questions
Is break-even fees divided by monthly saving?
That shortcut can fail when savings vary, fees are financed, or balances and terms differ; use cumulative cash flows.
Should I refinance to a longer term?
It may reduce near-term payment while extending debt and interest; compare the same horizon and ending balance.
What if I plan to move?
Use that expected date; savings projected after sale are irrelevant.
Further reading
Authoritative sources
Use these primary and professional resources to check definitions, conventions, or requirements that may extend beyond this guide.