The lump sum isn't a cost, but it isn't free either
Recasting's fee is small, but it locks up cash that could otherwise sit in savings or be invested — this tool doesn't try to price that trade-off for you. Refinancing needs no lump sum but comes with real closing costs and, usually, a new appraisal and credit check. See the Mortgage Refinance Calculator for a refinance-only deep dive, or the Mortgage Payoff Calculator to see the payoff-acceleration angle instead.
Frequently asked questions
What is a mortgage recast?
You pay a lump sum toward principal and the lender re-amortizes the remaining balance over the same remaining term at your existing rate — lowering the payment without a new loan, new credit check, or new closing costs. Not all lenders or loan types allow it.
When does refinancing win over recasting?
When rates have dropped enough that a new loan's lower rate saves more than a recast's principal reduction — and you don't need to tie up a lump sum to get there. Refinancing also lets you change the term, which recasting can't.
Does recasting save on total interest?
Yes, the same way any extra principal payment does — less balance accrues interest going forward. This tool focuses on the monthly payment and break-even, which is usually the more actionable comparison.
Last updated: June 2026