Mortgage Recast Calculator

Calculate your new monthly payment after making a lump sum payment and recasting your mortgage. Compare recast vs refinance and see total interest savings.

$
%
yrs
$
$
New Monthly Payment After Recast
$1,727
$345/month savings · $53,387 net interest saved
Current Payment
$2,073
New Payment
$1,727
Monthly Savings
$345
New Balance
$250,000
Interest Saved
$53,637
Net Savings (after fee)
$53,387
A recast keeps your rate and term — ideal if current rates are higher than your existing rate. No credit check required.

How to Use This Mortgage Recast Calculator

Enter your Current Balance, Interest Rate, and Years Remaining on your mortgage. Then add the Lump Sum Payment you plan to make and the Recast Fee your lender charges. The calculator shows your new payment after the lender re-amortizes the reduced balance over the same remaining term.

A recast does not change your interest rate or payoff date — it simply lowers your required monthly payment based on the smaller balance.

Mortgage Recast Formula

New Balance = Current Balance − Lump Sum Payment
New Payment = Monthly Payment(New Balance, Same Rate, Same Term)
Monthly Savings = Current Payment − New Payment
Interest Saved = Total Interest(Old Balance) − Total Interest(New Balance)
Net Savings = Interest Saved − Recast Fee

Example: $50,000 Lump Sum Recast

$300,000 Balance, 6.75%, 25 Years Remaining

Current Balance$300,000
Lump Sum Applied$50,000
New Balance After Recast$250,000
Current Monthly Payment$2,040
New Monthly Payment$1,700
Monthly Savings$340/mo
Interest Saved (lifetime)~$81,600
Recast Fee$250
Net Savings~$81,350

For $250 in fees, this homeowner saves $340/month and $81,000 in lifetime interest — one of the highest-ROI financial moves available to homeowners with existing low-rate mortgages.

Frequently Asked Questions

A mortgage recast is when you make a large lump sum payment toward principal and ask your lender to recalculate (re-amortize) your monthly payment based on the reduced balance. Your rate and remaining term stay the same — only the payment amount changes. It's also called loan re-amortization or mortgage re-amortization.
Making extra principal payments reduces your balance and shortens your payoff date but keeps your required payment the same. A recast reduces your required monthly payment to match the new lower balance. If your goal is lower cash flow requirements (freeing up monthly income), recast. If your goal is paying off faster, extra payments without recast achieve that.
Recast is ideal when: you receive a large lump sum (inheritance, bonus, sale of another property), current mortgage rates are higher than your existing rate (making refinancing counterproductive), you want lower monthly payments without starting a new loan, and you want to avoid the time and cost of full refinancing.
Requirements vary by lender but typically include: minimum lump sum of $5,000–$10,000, loan must be current (no late payments), recast fee payment ($150–$500), and the loan must be a conventional loan (FHA and VA loans are not eligible for recasting). Contact your loan servicer to confirm their specific requirements.
No. A recast does not involve a credit check, new loan origination, or any changes to your credit report. It's simply an internal adjustment to your existing loan's payment schedule. This is another advantage over refinancing, which involves a credit inquiry and full underwriting.

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