Methodology
How the Mortgage Recast Calculator works
How Tallivo computes your new monthly payment after a lump-sum principal payment when your lender re-amortizes the loan over the same remaining term.
The formula
new payment = amortize( balance − lump sum , same rate , same remaining term )
Step by step
- Apply the lump sum to the current balance to get the new, lower principal.
- Re-amortize that principal over the SAME remaining term at the SAME interest rate to get the new monthly payment.
- Monthly savings = old payment − new payment.
- Interest saved = remaining interest on the original balance − remaining interest on the recast balance, over the same term.
Assumptions & limitations
- The rate and payoff date are unchanged — that's what distinguishes a recast from a refinance.
- Excludes the servicer's recast fee (commonly $150–$500) and any minimum lump-sum requirement.
- Not all loans are eligible; many government-backed loans (FHA, VA, USDA) cannot be recast.
Sources
Model reviewed 2025. Figures are planning estimates, not a loan offer — this is not financial advice.