Mortgage recast calculator
See what a lump sum could do for your mortgage, or start with the monthly payment you want.
Your payoff outlook
Remaining principal after the lump sum and each monthly payment.
Check the highlighted loan details to update your results.
Use the arrow keys to move one month at a time. The remaining balances for that month follow the slider.
- Current loan
- Recast loan
- Pay off sooner
Compare the scenarios
Monthly P&I means principal and interest. Borrowing cost saved is interest saved minus any recast fee. The lump sum pays down principal.
Monthly amortization schedule
| Month | Payment | Principal | Interest | Ending balance |
|---|
The schedule starts after any lump sum. Any recast fee is paid separately. The final payment can differ from the regular amount shown above.
How mortgage recasting works
A recast lowers your required principal-and-interest payment after a lump sum reduces your balance. Your lender recalculates the payment using the same interest rate and remaining term.
How is a recast different from paying extra principal?
Both options reduce your balance immediately. A recast spreads that smaller balance over the remaining term to lower your required payment. If you keep making your current payment after the lump sum, you generally pay the mortgage off sooner and pay less interest.
How is a recast different from refinancing?
A recast changes the payment on your existing mortgage while preserving your rate and remaining term. A refinance replaces the mortgage with a new loan that can have a different rate, term, and closing costs.
Can I recast my mortgage?
Ask your servicer about eligibility, the minimum principal payment, fees, and when the new payment would start. Enter the fee they quote to compare the borrowing costs.
What if I invest the money instead?
If you keep some of the money invested, consider the risk of losses alongside potential returns. For options traders, Sharpe Two provides volatility forecasts and options-market research. This calculator compares mortgage costs only.
What assumptions does the calculator use?
Estimates use a fully amortizing fixed-rate loan, monthly interest, and a lump sum applied before the next payment. The recast fee is paid upfront. Payments exclude taxes, insurance, and other escrow charges. Timing, rounding, and servicer rules can change actual amounts.