Mortgage Recast Calculator

Calculate Your New Mortgage Payments After a Recast

Use this Mortgage Recast Calculator to see how a lump sum principal payment can reduce your monthly mortgage obligations without changing your interest rate or loan term.

Amortization Schedule After Mortgage Recast

Month	Starting Balance	Interest Payment	Principal Payment	Ending Balance

What is a Mortgage Recast?

A mortgage recast, sometimes called a re-amortization, is a process where a lender recalculates your monthly mortgage payments based on a reduced principal balance. This typically occurs after you’ve made a significant lump sum payment towards your mortgage principal. Unlike a refinance, a mortgage recast does not change your interest rate or the original term of your loan. Instead, it simply lowers your monthly payment by spreading the remaining principal balance over the existing loan term.

Who Should Consider a Mortgage Recast?

• Homeowners with a sudden windfall: If you receive a bonus, inheritance, or sell another property, a lump sum payment followed by a recast can significantly reduce your ongoing expenses.
• Those seeking lower monthly payments: If your goal is to free up cash flow without extending your loan term or incurring refinance costs, a mortgage recast is an excellent option.
• Individuals who want to avoid refinancing: Refinancing involves new closing costs, credit checks, and a potentially new interest rate. A mortgage recast avoids these complexities.
• People who have paid down a significant portion of their principal: Even without a large lump sum, some lenders may offer a recast if your principal balance has naturally decreased substantially.

Common Misconceptions About Mortgage Recasts

• It’s the same as a refinance: False. A refinance replaces your old loan with a new one, potentially changing the rate, term, and incurring significant closing costs. A recast only adjusts your payment based on a lower principal.
• It shortens your loan term: False. A standard mortgage recast keeps your original loan term intact. The benefit is a lower monthly payment, not a shorter repayment period. (Though some lenders might offer a “term recast” as a specific product, it’s not the default.)
• It’s always free: False. While much cheaper than a refinance, lenders typically charge a small fee for a mortgage recast, usually a few hundred dollars.
• All lenders offer it: False. Mortgage recasting is not universally offered by all lenders or for all loan types (e.g., FHA, VA, USDA loans often have restrictions). Always check with your specific lender.

Mortgage Recast Formula and Mathematical Explanation

The core of a mortgage recast calculation involves two main steps: first, determining your current remaining principal balance, and second, recalculating your monthly payment based on that new, lower principal over the remaining original term.

Step-by-Step Derivation:

1. Calculate Original Monthly Payment (P&I):

   The standard formula for a fixed-rate mortgage payment is:

   M = P [ i(1 + i)^n ] / [ (1 + i)^n – 1]

   Where:

   • M = Original Monthly Payment
   • P = Original Loan Amount
   • i = Monthly Interest Rate (Annual Rate / 12 / 100)
   • n = Original Loan Term in Months
2. Determine Remaining Principal Before Recast:

   This is the trickiest part. You need to calculate how much principal you’ve paid down over the months you’ve already made payments. This involves creating a mini-amortization schedule for the months paid so far.

   For each month:

   • Interest Paid = Current Balance * Monthly Interest Rate
   • Principal Paid = Original Monthly Payment - Interest Paid
   • New Balance = Current Balance - Principal Paid

   Repeat this for Months Paid So Far to find the Remaining Principal Before Recast.

3. Calculate New Principal After Recast:

   New Principal After Recast = Remaining Principal Before Recast - Lump Sum Payment

4. Determine Remaining Loan Term:

   Remaining Term in Months = Original Loan Term in Months - Months Paid So Far

5. Calculate New Monthly Payment (After Recast):

   Using the same mortgage payment formula as Step 1, but with the new values:

   New M = New P [ i(1 + i)^New n ] / [ (1 + i)^New n – 1]

   Where:

   • New M = New Monthly Payment
   • New P = New Principal After Recast
   • i = Monthly Interest Rate (remains the same)
   • New n = Remaining Term in Months

Variable Explanations and Typical Ranges:

Variable	Meaning	Unit	Typical Range
Original Loan Amount	The initial amount borrowed for the mortgage.	Dollars ($)	$50,000 – $1,000,000+
Original Interest Rate	The annual interest rate on the original loan.	Percentage (%)	2.5% – 8.0%
Original Loan Term (Years)	The initial duration of the mortgage.	Years	15, 20, 30
Months Paid So Far	The number of monthly payments already made.	Months	0 – (Original Term * 12 – 1)
Lump Sum Payment	The additional principal payment made to trigger the recast.	Dollars ($)	$5,000 – $100,000+
New Monthly Payment	The recalculated monthly payment after the recast.	Dollars ($)	Varies widely
Total Interest Saved	The total interest reduction over the remaining loan term due to the recast.	Dollars ($)	Varies widely

Practical Examples (Real-World Use Cases)

Example 1: Reducing Monthly Burden After a Bonus

Sarah has a 30-year mortgage with an original loan amount of $350,000 at a 4.0% interest rate. She’s been paying for 5 years (60 months). She recently received a large work bonus of $30,000 and wants to use it to lower her monthly payments.

• Original Loan Amount: $350,000
• Original Interest Rate: 4.0%
• Original Loan Term: 30 years
• Months Paid So Far: 60
• Lump Sum Payment: $30,000

Calculation Steps:

1. Original Monthly Payment: ~$1,671.06
2. Remaining Principal Before Recast (after 60 payments): ~$310,000
3. New Principal After Recast: $310,000 – $30,000 = $280,000
4. Remaining Term: 30 years * 12 months/year – 60 months = 300 months
5. New Monthly Payment (re-amortized over 300 months at 4.0%): ~$1,478.40

Financial Interpretation: Sarah’s monthly payment drops by approximately $192.66 ($1,671.06 – $1,478.40). This frees up nearly $200 each month in her budget, providing significant cash flow relief without changing her loan term or interest rate. Over the remaining 25 years, she also saves a substantial amount in total interest.

Example 2: Using Proceeds from a Property Sale

David sold an investment property and has $75,000 he wants to put towards his primary residence mortgage. His current mortgage was originally $450,000 at 3.5% over 20 years. He’s 8 years (96 months) into the loan.

• Original Loan Amount: $450,000
• Original Interest Rate: 3.5%
• Original Loan Term: 20 years
• Months Paid So Far: 96
• Lump Sum Payment: $75,000

Calculation Steps:

1. Original Monthly Payment: ~$2,609.90
2. Remaining Principal Before Recast (after 96 payments): ~$295,000
3. New Principal After Recast: $295,000 – $75,000 = $220,000
4. Remaining Term: 20 years * 12 months/year – 96 months = 144 months
5. New Monthly Payment (re-amortized over 144 months at 3.5%): ~$1,600.00

Financial Interpretation: David’s monthly payment decreases by over $1,000 ($2,609.90 – $1,600.00). This massive reduction significantly improves his monthly cash flow, allowing him to pursue other financial goals or simply enjoy a much lower housing expense for the remainder of his loan term. The total interest saved will also be very substantial.

How to Use This Mortgage Recast Calculator

Our Mortgage Recast Calculator is designed to be user-friendly and provide clear insights into your potential savings. Follow these steps to get your personalized results:

1. Enter Original Loan Amount: Input the initial principal amount of your mortgage.
2. Enter Original Interest Rate (%): Provide the annual interest rate of your original loan.
3. Enter Original Loan Term (Years): Specify the initial duration of your mortgage in years (e.g., 15, 30).
4. Enter Months Paid So Far: Input the total number of monthly payments you have already made on your mortgage.
5. Enter Lump Sum Payment for Recast ($): This is the additional principal payment you plan to make to trigger the recast.
6. Click “Calculate Recast”: The calculator will automatically update the results in real-time as you adjust inputs, but you can also click this button to ensure all calculations are fresh.

How to Read the Results:

• New Monthly Payment: This is your primary result, highlighted prominently. It shows your new, lower principal and interest payment after the recast.
• Original Monthly Payment: For comparison, this shows what your payment was before the lump sum and recast.
• Remaining Principal Before Recast: The outstanding balance on your loan just before you make the lump sum payment.
• New Principal After Recast: Your outstanding balance immediately after the lump sum payment is applied.
• Total Interest Saved (Remaining Term): This crucial metric shows the total amount of interest you will save over the remaining life of the loan due to the reduced principal.

Decision-Making Guidance:

The results from this Mortgage Recast Calculator can help you decide if a recast is the right move. Compare the “New Monthly Payment” to your current budget and see if the “Total Interest Saved” aligns with your long-term financial goals. Remember to factor in any potential recast fees charged by your lender.

Key Factors That Affect Mortgage Recast Results

Several variables play a significant role in determining the impact of a mortgage recast. Understanding these factors can help you maximize the benefits of this financial strategy.

• Lump Sum Payment Amount: This is the most direct factor. A larger lump sum payment will result in a greater reduction of your principal balance, leading to a more substantial decrease in your new monthly payment and higher total interest savings.
• Original Interest Rate: While the recast doesn’t change your rate, the original rate significantly influences the interest portion of your payments. A higher original interest rate means a larger portion of your payment goes to interest, and thus, reducing the principal has a more pronounced effect on future interest accrual and savings.
• Remaining Loan Term: The longer your remaining loan term, the more time the reduced principal has to compound interest savings. A recast earlier in your loan’s life, with many years remaining, will generally yield greater total interest savings than one performed near the end of the term.
• Months Paid So Far: This affects the remaining principal before the recast. If you’ve paid many months, a significant portion of your early payments went to interest, meaning your principal might not have reduced as much as you think. The calculator accurately accounts for this.
• Lender Fees: Most lenders charge a small administrative fee for a mortgage recast, typically a few hundred dollars. While much less than refinance closing costs, this fee should be factored into your decision.
• Opportunity Cost of Funds: Consider what else you could do with the lump sum payment. Could it generate a higher return elsewhere (e.g., investments) or be better used to pay off higher-interest debt (e.g., credit cards, personal loans)? The benefit of a recast should outweigh these alternative uses.

Frequently Asked Questions (FAQ)

Q: What’s the main difference between a mortgage recast and a refinance?

A: A mortgage recast reduces your monthly payment by re-amortizing your loan after a lump sum principal payment, keeping your original interest rate and term. A refinance replaces your old loan with a completely new one, potentially changing the rate, term, and incurring significant closing costs.

Q: Does a mortgage recast affect my credit score?

A: Generally, no. A mortgage recast is an administrative adjustment to your existing loan, not a new loan application. It typically does not involve a hard credit inquiry and therefore has no direct impact on your credit score.

Q: How much does a mortgage recast cost?

A: The cost is usually an administrative fee charged by your lender, typically ranging from $150 to $500. This is significantly less expensive than the thousands of dollars in closing costs associated with a refinance.

Q: Can I recast any type of mortgage?

A: Not all mortgages are eligible. Conventional loans are most commonly recast. FHA, VA, and USDA loans often have specific rules or may not allow recasting. Always check with your specific lender and loan type.

Q: Is there a minimum lump sum payment required for a recast?

A: Yes, most lenders require a minimum lump sum payment, often ranging from $5,000 to $10,000 or more, to make the recast worthwhile for them administratively. Check with your lender for their specific requirements.

Q: Will a recast shorten my loan term?

A: A standard mortgage recast does not shorten your loan term. It keeps the original term but lowers your monthly payments. If you want to shorten your term, you would typically need to refinance or make extra principal payments without a recast.

Q: When is the best time to consider a mortgage recast?

A: A recast is most beneficial when you have a significant lump sum of cash and your primary goal is to reduce your monthly expenses without changing your interest rate or incurring high refinance costs. It’s particularly impactful earlier in your loan term when interest makes up a larger portion of your payments.

Q: What if my lump sum payment is larger than my remaining principal?

A: If your lump sum payment exceeds your remaining principal, you would effectively pay off your mortgage in full. A recast would not be necessary in this scenario, as the loan would be closed.

Related Tools and Internal Resources

• Mortgage Payment Calculator: Calculate your standard monthly mortgage payments based on loan amount, interest rate, and term.
• Amortization Schedule Calculator: See a detailed breakdown of principal and interest payments over the life of your loan.
• Mortgage Refinance Calculator: Compare your current mortgage with potential refinance options to see if a new loan makes sense.
• Extra Mortgage Payment Calculator: Discover how making additional principal payments can shorten your loan term and save interest.
• Loan Comparison Tool: Compare different loan scenarios side-by-side to find the best option for your financial situation.
• Debt Consolidation Guide: Learn strategies for combining multiple debts into a single, more manageable payment.