Mortgage recast calculator
Estimate a lower payment after a lump-sum principal reduction and mortgage recast.
What this calculator covers
Use this calculator to estimate how a lump-sum principal payment may change the payment after a mortgage recast.
The walkthrough keeps the reduced balance, new payment, and fee payback period visible together.
Frequently asked questions
- How is a mortgage recast different from refinancing?
- A recast keeps your existing loan — same rate, same lender, same remaining term — and simply recalculates the payment on the reduced principal after you make a lump-sum contribution. Refinancing replaces the loan entirely, which usually involves closing costs, a new rate, and a new term.
- Does every lender offer mortgage recasting?
- Not all lenders offer recasting, and some loan types such as FHA and VA loans are generally not eligible. Contact your loan servicer directly to confirm whether your loan qualifies and what fee they charge.
- What is the fee break-even period shown in the results?
- The break-even period is how many months of monthly savings it takes to recover the recast fee. If the fee is $300 and the payment drops by $100 per month, the break-even is 3 months. After that point, every month produces net savings.
- Does a recast change my loan's interest rate or end date?
- No. The interest rate and remaining term stay exactly the same after a recast. Only the monthly payment changes because it is recalculated on the lower outstanding balance spread over the same remaining months.
Tool
Run the calculation
Result
RESULT · RECAST PAYMENT
â„–051
Primary result
$1,649.17
Applying $50,000.00 to a $300,000.00 balance and recasting the loan over 25 years lowers the payment from about $1,979.01 to $1,649.17, saving about $329.84 per month.
- Current monthly payment
- $1,979.01
- Recast balance
- $250,000.00
- Recast monthly payment
- $1,649.17
- Monthly savings
- $329.84
- Fee break-even
- 1 month
Step-by-step solution
- 1.Estimate the current payment on the remaining balance and term to get $1,979.01 per month.
- 2.Subtract the lump-sum payment from the current balance to leave $250,000.00 for the recast calculation.
- 3.Amortize the lower balance over the same remaining term to estimate $1,649.17 per month and about 1 month to recover the recast fee.
Walkthrough
Visual walkthrough
A mortgage recast applies a lump sum to principal, then recalculates the payment over the remaining term rather than changing the rate or replacing the loan.
01
Find the current payment
The remaining balance, rate, and remaining term define the current scheduled payment.
$1,979.01 current payment
02
Reduce the balance with the lump sum
$300,000.00 - $50,000.00 = $250,000.00
The lump-sum payment reduces the principal before the payment is recalculated.
$250,000.00 recast balance
03
Read the new payment and fee payback
The lower balance usually produces a lower payment, and the monthly savings can be compared with any recast fee.
$1,649.17 new payment / 1 month