Mortgage Recast Calculator
See your new payment after a lump-sum recast.
Results update as you type.
How it works
A mortgage recast, or reamortization, lowers your monthly payment after you make a large lump-sum payment toward principal, and this calculator shows the new payment and savings. You enter your current loan balance, the lump sum you plan to pay, your interest rate, and the remaining term, and it returns your new monthly payment, your current payment, and the monthly savings. Unlike refinancing, a recast keeps your existing interest rate and loan term; the lender simply recalculates your payment based on the lower balance after your lump-sum payment, spread over the same remaining months. This reduces the payment while keeping the original payoff date. Recasting is attractive when you come into a windfall, sell another property, or otherwise have a large sum to put toward the mortgage and want lower payments without the cost and hassle of refinancing. It usually carries only a small administrative fee, far less than refinancing closing costs, and does not require a credit check or appraisal. The trade-off compared to simply making an extra principal payment is that recasting lowers your payment rather than shortening your term, so you free up monthly cash flow instead of paying the loan off faster. Not all loans are eligible; many conventional loans allow recasting, but government-backed loans often do not, so check with your lender. Enter your balance, lump sum, rate, and term to see the recast result.
New payment = amortize (balance − lump sum) over the remaining term
A recast keeps your interest rate and remaining term but recalculates the monthly payment on the lower balance after a lump-sum principal payment. The new payment amortizes the reduced balance over the same remaining months, lowering the payment while the payoff date stays the same.
Source:Mortgage amortization
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Worked example
How to use this calculator
- 1
Enter your values
Enter current loan balance, lump-sum payment, interest rate and remaining term.
- 2
Adjust the options
Fine-tune any options to match your situation.
- 3
Read your result
New monthly payment updates instantly as you type — no button to press.
Frequently asked questions
What is a mortgage recast?
A mortgage recast, or reamortization, is when a lender recalculates your monthly payment after you make a large lump-sum payment toward the principal. Your interest rate and remaining term stay the same, but the payment drops because it is spread over the lower balance. It lowers your payment without refinancing.
How is a recast different from refinancing?
Refinancing replaces your loan with a new one, potentially at a different rate and term, and involves closing costs, a credit check, and an appraisal. A recast keeps your existing loan, rate, and term, only recalculating the payment on a lower balance after a lump sum. It is far cheaper and simpler but does not change your interest rate.
Should I recast or just make extra payments?
Both apply your lump sum to principal, but recasting lowers your monthly payment while keeping the payoff date, whereas making extra payments without recasting keeps your payment the same and shortens the term. Choose recasting to improve monthly cash flow, or extra payments to pay off the loan faster and save more total interest.
How much does a recast cost?
Recasting typically involves a small administrative fee, often a few hundred dollars, far less than the thousands in closing costs a refinance requires. There is usually no credit check or appraisal. This low cost is a key advantage, making recasting an economical way to lower payments when you have a lump sum to apply.
Can any mortgage be recast?
No. Eligibility depends on your loan and lender. Many conventional loans allow recasting, often requiring a minimum lump-sum amount, but government-backed loans such as FHA, VA, and USDA loans generally do not permit recasting. Check with your lender or servicer to confirm whether your specific mortgage is eligible before planning a recast.