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Infinix Calculators
Mortgage & Loans

Mortgage Recast Calculator

Calculate your new lower monthly mortgage payment and interest savings after making a lump-sum principal recast payment.

Interactive Calculator

1. Provide Details

$
%
yrs
$

2. Output Results

New Recast Monthly Payment$1688.02
Monthly Payment Savings$337.60
New Loan Principal Balance$250000.00
Original Monthly Payment$2025.62

How to Calculate: Formula & Steps

The lender re-amortizes the reduced loan balance over the remaining term length.

Formula Used:New Payment = Amortize(Remaining Principal - Lump Sum, Interest Rate, Remaining Months)

Step-by-Step Calculation Example

Lump sum of $50,000 on a $300,000 mortgage reduces monthly payment significantly while maintaining existing rate.

Inputs and Assumptions

Enter values that match your project or situation. The calculator uses the following fields and defaults; update them before relying on the estimate.

Current Loan Principal Balance ($)
Default: 300000 $
Mortgage Interest Rate (%)
Default: 6.5 %
Remaining Term (Years)
Default: 25 yrs
Lump-Sum Recast Payment ($)
Default: 50000 $

Common Mistakes to Avoid

  • Confusing recast with refinancing
  • Assuming all lenders offer zero-fee recasting

Practical Use Cases

  • Lump sum windfall application
  • Lowering monthly fixed expenses

Expert Tips

  • Check if your mortgage servicer charges a minor recast processing fee ($150-$300).

Mortgage Recast vs Refinance: What's the Real Difference?

A mortgage recast (also called a "re-amortization") lets you apply a lump-sum payment toward your principal balance while keeping your original interest rate, loan term, and closing costs unchanged. The lender simply re-calculates a lower monthly payment based on the reduced balance over the remaining term.

Recast Keeps Your Rate

Unlike refinancing, a recast does not require a new credit check, new appraisal, or new closing disclosure. It typically only costs a small $150–$300 processing fee, making it far cheaper than a full refinance.

Not All Lenders & Loans Qualify

Most conventional loans allow recasting, but FHA, VA, and USDA loans generally do not. Check with your loan servicer to confirm eligibility and any minimum lump-sum requirement (often $5,000–$10,000+).

Recast Payment Formula

New Payment = Amortize(Balance − Lump Sum, Same Rate, Same Remaining Term)

Example: A $50,000 lump sum on a $300,000 balance at 6.5% with 25 years remaining meaningfully lowers the monthly P&I payment while the loan payoff date stays exactly the same.

Recast vs Extra Principal Payments

Making extra principal payments without recasting shortens your loan term but keeps the monthly payment the same. Recasting instead lowers the monthly payment immediately — ideal for homeowners who want reduced fixed monthly obligations rather than an earlier payoff date.

Disclaimer

This calculation tool is provided for educational and informational estimation purposes only. Results are based on mathematical formulas and user-supplied parameters. They do not constitute formal underwriting, financial, tax, engineering, or legal determinations.

Frequently Asked Questions About Mortgage Recast Calculator

How does an interest-only HELOC work during the draw period?
During the initial draw period (typically 10 years), your monthly HELOC payment covers only accrued interest on the drawn balance. Once the repayment period begins (usually 10-20 years), monthly payments rise as principal amortizes.
What is a mortgage recast vs refinancing?
A mortgage recast allows you to make a lump-sum principal payment while keeping your existing interest rate and loan term. The lender recalculates (re-amortizes) your monthly payment to lower it, whereas refinancing replaces your loan with a new rate and term.
Vaughn Mercer portrait
Editorial contact: Vaughn Mercer
Editorial policyEstimate only