Recast Mortgage Calculator

Category: Mortgage and Real Estate
- May 14, 2025
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Calculate how recasting your mortgage can affect your monthly payments and overall interest. Recasting (also called re-amortization) keeps your interest rate and term the same, but applies a lump sum payment to reduce principal and recalculates your monthly payments.

Current Mortgage Details

$
$
%
$
Principal and interest only (no taxes or insurance)

Recast Details

$
$
One-time fee charged by lender

Alternative Options

Understanding Mortgage Recasting

Mortgage recasting (also called re-amortization) is when you make a large lump sum payment toward your mortgage principal, and your lender recalculates your monthly payments based on the new, lower principal balance. Unlike refinancing, recasting keeps your interest rate and loan term the same.

Benefits of Recasting
  • Lower monthly payments: Your required monthly payment decreases based on the reduced principal
  • Low cost: Typically involves a small fee ($250-$500) versus thousands for refinancing
  • No credit check: No impact on your credit or debt-to-income ratio
  • Interest savings: Less interest paid over the life of the loan
  • Simple process: Less paperwork and faster than refinancing
When to Consider Recasting
  • When you've come into a large sum of money (inheritance, bonus, sale of assets)
  • When you've sold a previous home and want to apply proceeds to your new mortgage
  • When you have a low mortgage interest rate that you don't want to change
  • When you want to reduce monthly payments but keep your loan term the same
  • When refinancing costs would be too high or you don't qualify for refinancing
Recast vs. Extra Payments vs. Refinance
Feature Recasting Extra Payments Refinancing
Interest Rate Unchanged Unchanged Can be lower
Loan Term Unchanged Shortened Can be changed
Monthly Payment Reduced Unchanged Usually reduced
Typical Cost $250-$500 $0 $2,000-$5,000+
Credit Check No No Yes
Process Simple Simplest Complex

Disclaimer: This calculator provides estimates based on the information entered. Results may vary based on your specific loan terms, payment history, and lender policies. Not all mortgages are eligible for recasting. Please consult with your lender for specific details about your mortgage and recasting options.

What Is the Recast Mortgage Calculator?

The Recast Mortgage Calculator is a simple mortgage payment tool designed to help you understand how making a lump sum payment on your home loan can lower your monthly payments. Unlike refinancing, recasting keeps your original interest rate and loan term intact, making it a useful option for reducing payments without starting a new loan.

This calculator is part of a broader set of home financing planners and mortgage payment guides, offering insights into your property financing options.

How Does Recasting Work?

Mortgage recasting, also called re-amortization, involves making a one-time lump sum payment toward your principal. Your lender then recalculates your monthly payment based on the new lower balance, but your interest rate and loan end date remain the same.

This can help lower your monthly mortgage costs without the high fees or paperwork of refinancing.

Recast Mortgage Formula

New Monthly Payment = P × [r(1 + r)n] / [(1 + r)n – 1]
  • P = Remaining loan balance after lump sum payment
  • r = Monthly interest rate (annual rate ÷ 12 ÷ 100)
  • n = Remaining loan term in months

Why Use This Calculator?

This mortgage cost planner helps you:

  • Estimate your new monthly payment after a recast
  • Compare recasting with refinancing or making extra payments
  • See how much interest you could save over the life of your loan
  • Understand the tradeoffs between lower payments and faster payoff

It's a helpful addition to your home financing guide when you're exploring strategies to manage or lower your debt.

How to Use the Calculator

  1. Enter your current mortgage details, including loan amount, balance, interest rate, term, and start date.
  2. Add the lump sum amount you plan to pay and any recast fee your lender charges.
  3. Optionally, compare with refinancing by checking the box and entering the new rate, term, and closing costs.
  4. Click Calculate to see your new monthly payment, interest savings, and comparison charts.

Key Features

  • Estimates new payment based on a lump sum applied to the loan balance
  • Breaks down monthly savings and total interest saved
  • Includes amortization schedule for detailed payment structure
  • Compares recasting with refinancing and extra payments
  • Includes helpful charts for a quick visual overview

When Is Recasting Useful?

Recasting can be especially beneficial if:

  • You’ve received a windfall such as a bonus, inheritance, or home sale proceeds
  • You want to reduce your monthly mortgage payment without changing your interest rate
  • You prefer a quick and low-cost process compared to refinancing
  • You have a fixed interest rate you want to keep

Frequently Asked Questions (FAQ)

Does recasting lower my interest rate?

No, recasting does not change your interest rate. It only recalculates your monthly payment based on a lower principal balance.

Will my loan term change?

No. The term (years left on your loan) stays the same, but your required monthly payment decreases.

Can I recast any mortgage?

Not always. Some lenders don’t offer recasting or only allow it on certain loan types. Check with your lender first.

What’s the difference between recasting and refinancing?

Recasting lowers your payment with a lump sum but keeps your rate and term. Refinancing replaces your loan, potentially with a new rate and term, but often with higher upfront costs and more paperwork.

Is this calculator accurate for all loan types?

It provides helpful estimates, but actual results may vary. Always consult your lender or a Financial advisor before making decisions.

Final Thoughts

Whether you're using this tool as a mortgage payment guide, a monthly loan breakdown aid, or simply exploring your options with a home loan estimate, the Recast Mortgage Calculator is a practical way to understand how a lump sum payment can change your monthly financial picture.

It combines elements of a mortgage amortization calculator, a refinance savings tool, and a loan Interest Calculator to give you clear, useful results you can act on.