Mortgage Recast Calculator — Lower Your Payment Without Refinancing

See how much a lump-sum principal payment lowers your monthly mortgage payment via recasting — same rate, same payoff date, no refinance.

July 3, 2026

Current Remaining Balance ($)

Interest Rate (%)

Remaining Term (years)

Lump-Sum Principal Payment ($)

Recast Fee ($, optional)

Current Payment

$1,933/mo

New Payment After Recast

$1,611/mo

Monthly Savings

$322/month

Recast fee pays for itself in ≈1 month.

Monthly Payment = Principal × [r(1+r)ⁿ] ÷ [(1+r)ⁿ − 1], where r is the monthly interest rate and n is the number of remaining payments. Recasting keeps your original rate and payoff date — only the payment is recalculated on the reduced balance. FHA, VA, and USDA loans are generally not eligible for recasting; conventional loans (including jumbo and Fannie Mae/Freddie Mac loans) usually are.

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Reference Values

Last verified: Jul 2, 2026

Category	Range	What It Means	Status
Typical minimum lump sum required	$5,000+	Most lenders require a minimum principal paydown to approve a recast — varies by servicer.	Good
Typical recast fee ★	≈$150–$500	A one-time administrative fee, far less than refinance closing costs.	★ Best
Loan term after recast	Unchanged	Recasting keeps your original payoff date and interest rate — only the monthly payment is recalculated.	Good
Eligible loan types	Conventional (incl. jumbo, Fannie/Freddie)	FHA, VA, and USDA loans are generally NOT eligible for recasting.	Okay
Refinance closing costs (for comparison)	2–6% of loan balance	What you'd pay instead if you refinanced rather than recast — recasting has no appraisal, credit check, or closing costs.	Poor

Source: Mortgage recast mechanics, eligibility, and typical fee ranges aggregated from Bankrate and standard mortgage-servicer recast policies.

Worked Examples

$50,000 Lump Sum on a $300,000 Balance

Remaining Balance: $300,000
Rate: 6.0%
Remaining Term: 25 years
Lump Sum: $50,000

Payment drops from ≈$1,933 to ≈$1,611/month (≈$322/month savings)

Same rate and remaining term, but the payment is recalculated on the new $250,000 balance instead of $300,000 — the payoff date doesn't change, only the monthly payment.

Small Lump Sum, Minimal Impact

Remaining Balance: $300,000
Rate: 6.0%
Remaining Term: 25 years
Lump Sum: $10,000

Payment drops from ≈$1,933 to ≈$1,868/month (≈$65/month savings)

A smaller lump sum still lowers the payment, but proportionally less — recasting rewards larger principal paydowns.

How to Use This Calculator

1

Enter your current remaining balance, rate, and remaining term

From your latest mortgage statement.
2

Enter the lump-sum payment you're considering

The amount you'd pay toward principal to trigger the recast.
3

Enter the recast fee, if known

Optional — most lenders charge a small one-time fee, often $150–$500.
4

Compare your current and new payment

Shows your monthly savings and how quickly the recast fee pays for itself.

What Each Value Means

New Payment After Recast ($/month): Your recalculated monthly payment based on the reduced principal balance, same interest rate, and same remaining term.
Monthly Savings ($/month): The difference between your current payment and your new, recast payment.

Frequently Asked Questions

What is mortgage recasting?

Recasting is when you make a large lump-sum payment toward your mortgage principal, and your lender recalculates (re-amortizes) your monthly payment based on the new, lower balance — while keeping your original interest rate and payoff date exactly the same. It's different from a extra-payment that just shortens your loan; a recast specifically lowers your required monthly payment going forward.

How is mortgage recasting different from refinancing?

Refinancing replaces your loan entirely with a new one — new rate, new term, new closing costs (typically 2–6% of the loan balance), a new appraisal, and a new credit check. Recasting keeps your existing loan and rate, requires no appraisal or credit check, and costs a small one-time fee (often $150–$500) instead of full closing costs. The tradeoff is that recasting can't get you a better rate — refinancing can, if rates have dropped.

What loans are eligible for recasting?

Conventional loans — including jumbo loans and those backed by Fannie Mae or Freddie Mac — are generally eligible. FHA, VA, and USDA government-backed loans are generally NOT eligible for recasting; if you have one of these loan types, refinancing or simply making extra principal payments (without a formal recast) are your main options for reducing your payment.

Is there a minimum lump sum required to recast?

Yes — most lenders require a minimum principal paydown, commonly $5,000 or more, before they'll approve a recast. Check with your specific loan servicer, since minimums and whether recasting is offered at all vary by lender.

Does recasting save me money on total interest paid?

Yes, though less dramatically than paying off the loan early outright. Because your balance is lower for the remainder of the term, less interest accrues overall compared to not making the lump-sum payment — but since your payoff date doesn't move up, you don't get the larger interest savings you'd see from also shortening the term.