Housing
When a mortgage refinance beats extra principal, how to count closing costs, and why shortening the term is not the same as lowering the rate.
Updated 2026-09-08 · 8 min read
A lower rate on the same remaining term is the clean win. Refinancing a 23-year-old 30-year loan into a new 30-year loan can lower the payment and *increase* lifetime interest. If you refinance, match or shorten the remaining term unless cash-flow is the actual goal.
One extra payment a year, or a modest monthly extra, cuts years without closing costs. Compare that guaranteed mortgage rate to what you could earn after tax in the market. The premium extra-vs-invest calculator exists for this fight.
Run the numbers: extra vs invest calculator (All Access). Rate-and-term closing costs: refinance break-even.
Closing costs divided by monthly savings. If you might move before that month, do not refinance — or negotiate a lender credit and accept a slightly higher rate.
Educational only. Verify IRS limits and loan quotes before acting.