Refinancing

Replacing an existing loan with a new one, usually at a lower rate or different term. The old loan is paid off in full by the new one.

Reviewed May 2026.

Refinancing makes sense when the new rate is meaningfully lower than the old, or when you need a different term length. The classic rule of thumb for mortgages: refi pays off if the new rate is at least 0.75 percentage points lower and you'll stay in the home long enough to recover closing costs (typically 12-24 months).

For auto loans: refi works when your credit score has improved 50+ points since origination, or when rates have dropped. There are usually no closing costs.

For student loans: refinancing federal loans into a private lender locks in a (usually lower) rate but forfeits forgiveness eligibility, income-driven repayment, and discharge protections. Generally only worth it for high-income borrowers with no plans to use those programs.

Refinancing is not free — closing costs on mortgages are 2-5% of the loan amount. Run break-even math before you sign.

PayoffMath angle. Refi math hinges on the term-extension trap: keep the remaining months the same and refinance to a lower rate, and you usually win. Reset the term to a fresh 30 years and refinance to a lower rate, and you often lose on lifetime interest while winning on monthly cash flow.

Why it matters. Refinancing is one of the two main payoff-math levers (the other is prepayment). Knowing when to refi vs prepay vs do both is usually worth more than picking the optimal extra-payment amount.

Common mistake. Refinancing into a 'fresh' 30-year loan to chase a lower rate often increases total interest paid, because you reset the amortization clock. The monthly drop is real; the lifetime savings often aren't.

Try the refinance break-even calculator → — compute break-even months + lifetime interest delta + the verdict (strict win, term extension, term shortening, refi loses).

Worked example

Example: a 30-year mortgage at 7.5% with $250k remaining and 25 years left. Refi to 6.0% over 25 years saves about $260/month and $78,000 over the life. Closing costs of $7,500 are recovered in 29 months — worth it if you'll stay 3+ years.

See also

Sources and review

Reviewed May 2026. Glossary entries are plain-language definitions, not legal definitions. For account-specific rules, your loan documents control.

Definition by James L. Wu. Plain-language gloss, not a legal definition. For terms that show up in your loan paperwork, the governing language is in your loan documents. See the editorial policy for sourcing.