Mortgage Recast Calculator
What lenders don’t want
you to know about
your mortgage payment.
A mortgage recast can cut your monthly payment by hundreds of dollars with no new loan, no credit check, and no rate requirement. Lenders process them reluctantly — here is why, and how to make them do it anyway.
I put $73,000 toward a $360,000 mortgage. That single payment dropped my monthly obligation by more than $400. Every dollar of that reduction is pure interest I no longer owe the bank. The process cost me $500. The math was not complicated. What was complicated was getting the lender to process it.
Nine phone calls. Three weeks. Agents who did not know what a recast was. Supervisors who did. An unnecessary extra month of delay that cost me roughly $450 in interest I did not have to pay. When it finally processed, my payment dropped immediately and permanently — no new loan, no credit check, no closing costs, no rate change, no reset of my amortization clock.
There is a reason your lender does not advertise this option. There is a reason the agents you speak to are undertrained on it. There is a reason the process takes longer than it should. A mortgage recast is one of the most powerful tools available to a homeowner, and it costs the lender money every single month after you do it.
A recast saves you money every month, forever. That is exactly why your lender makes it difficult.
What a mortgage recast actually is
A mortgage recast — also called re-amortization — is when you make a lump sum payment toward your principal and ask your servicer to recalculate your monthly payment based on the new, lower balance. Your interest rate stays the same. Your loan term stays the same. Your remaining timeline to payoff stays the same. The only thing that changes is how much you owe, which means the interest calculated on that balance drops — and so does your required monthly payment.
The fee varies by lender but typically runs $150 to $500. There is no appraisal. No credit check. No new loan. No closing costs. No title insurance. No underwriting. You call your servicer, make the lump sum payment, pay the recast fee, and your payment recalculates — usually within 30 to 60 days.
Who qualifies: Conventional loans serviced by most major banks and credit unions allow recasting. FHA, VA, and USDA loans typically do not. Jumbo loans vary by servicer. If you are not sure whether your loan qualifies, call your servicer and ask directly — “Do you offer mortgage recasting, and does my loan type qualify?”
Why the biweekly mortgage payment serves the bank more than you
The biweekly payment strategy is one of the most widely marketed mortgage acceleration techniques. The pitch is simple: pay half your monthly payment every two weeks instead of once a month. Because there are 26 two-week periods in a year instead of 24, you end up making 13 full monthly payments instead of 12. One extra payment per year, every year, can cut years off your loan and save tens of thousands in interest.
The math is real. The strategy works. But it is not the best use of that money — and the bank knows it.
Here is what the biweekly pitch does not tell you. When you make extra payments under a biweekly schedule, those payments eliminate months from the back end of your loan. The payments in years 27, 28, and 29 of a 30-year mortgage. By that point in your amortization schedule, those payments are almost entirely principal anyway — the interest portion has already dwindled to a small fraction of each payment. The interest savings on eliminating those late payments is real, but it is the least efficient place to attack your loan.
Now consider what happens if instead of sending half-payments every two weeks, you save that same money in a high-yield savings account for two or three years. Then you take that lump sum, apply it to your principal during the years when your amortization is still heavily front-loaded, and request a recast. You attack the balance when the interest multiplier is at its maximum. The reduction in interest is immediate and permanent. And your monthly payment drops — giving you flexibility that a biweekly program never provides.
The biweekly program fee trap: Many lenders and third-party services charge a setup fee of $200 to $400 to enroll in a biweekly payment program. Some charge ongoing monthly fees. You can achieve the same result by making one extra principal payment per year yourself — for free. If your lender is selling you a biweekly program with a fee, that alone tells you something about whose interest the program serves.
Mortgage recast vs. refinance vs. biweekly — the honest comparison
| Mortgage recast | Refinance | Biweekly payments | |
|---|---|---|---|
| Cost | $150 to $500 | $8,000 to $15,000 | $0 to $400 setup fee |
| Credit check required | No | Yes | No |
| Resets amortization clock | No | Yes — back to month 1 | No |
| Lowers monthly payment | Yes — immediately | Yes — if rate drops | No — payment stays same |
| Rate requirement | None — keep current rate | Must qualify for lower rate | None |
| Attacks interest efficiently | Yes — at peak front-loading | Depends on timing | Attacks low-interest tail end |
| Lender advertises it | Rarely | Actively | Sometimes, with fees |
| Lender profits from it | No — reduces their interest revenue | Yes — fees plus new interest | Marginally |
Why lenders don’t want you to recast your mortgage
A refinance generates origination fees, title insurance, appraisal costs, and potentially years of additional interest on a new loan. Every time you refinance, the lender starts the amortization clock over — which means you go back to paying mostly interest from month one. The lender collects a substantial fee upfront and then benefits from the front-loaded interest structure all over again.
A mortgage recast generates a $500 administrative fee — once — and then permanently reduces the interest you pay every single month for the life of the loan. There is no upside for the lender. Every month after your recast, the bank collects less money from you than it did before. The $500 fee does not come close to covering what they lose in interest revenue over the remaining term.
This is why agents are undertrained on it. This is why the process takes longer than it should. This is why you may be told you need to wait for a “specialist” who calls back in three to five business days. None of this is coincidental. An institution that profits from your interest payments has no financial motivation to efficiently process a transaction that permanently reduces those payments.
From personal experience: Nine calls over three weeks. Agents who did not know what a recast was. A supervisor who did but said the processing team was “backed up.” An escalation that went nowhere for two weeks. A final escalation that pushed it through — but not before an extra month of unnecessary delay cost roughly $450 in interest that did not need to be paid. The recast itself was straightforward. Getting the lender to process it was not.
How to request a mortgage recast — and what to do when they drag their feet
Confirm your loan qualifies
Call your servicer — the number on your monthly statement — and ask: “Does my loan type qualify for a mortgage recast?” Conventional loans almost always qualify. FHA, VA, and USDA generally do not. Get the answer in writing if possible — ask them to email you confirmation.
Ask for the minimum lump sum and the fee
Most servicers require a minimum lump sum — commonly $5,000 to $10,000, though this varies. The fee is typically $150 to $500. Get both numbers confirmed before you proceed. Some servicers charge nothing. Ask specifically: “What is the minimum lump sum required, and what is the recast fee?”
Submit the lump sum payment and recast request in writing
Make the lump sum payment designated specifically as a principal payment — not a regular payment. Then submit the recast request in writing. Ask for email confirmation that the recast request has been received and is being processed, with an expected completion timeline.
Follow up in writing — not just by phone
If you do not receive a processing confirmation within five business days, follow up in writing. Email creates a paper trail that phone calls do not. Reference your request date, your lump sum payment confirmation number, and ask for a specific completion date. Keep every email.
Escalate immediately if the timeline slips
If the servicer misses their own stated timeline, ask immediately to speak with a supervisor or the mortgage servicing department manager. State clearly: “My recast has been delayed beyond the timeline I was given. Every month of delay costs me money in unnecessary interest. I need this processed this week.” Use the word “escalate” explicitly.
File a complaint if necessary
If escalation within the servicer does not resolve the delay, file a complaint with the Consumer Financial Protection Bureau at consumerfinance.gov/complaint. Servicers respond quickly to CFPB complaints. You can also contact your state’s banking regulator. The CFPB complaint alone is often enough to get immediate action.
The delay cost calculation: Every month your lender delays processing your recast, you continue paying interest on the pre-recast balance. On a $360,000 loan at 6.5%, that is approximately $450 per month in interest that would have been eliminated if the recast had processed on time. The calculator above includes a delay cost field — enter the number of months your lender took beyond their stated timeline to see exactly what their friction cost you.
When a mortgage recast makes the most sense
A recast is most powerful when applied early in the loan, when the amortization is still heavily front-loaded. In the first several years of a 30-year mortgage, the majority of every payment goes to interest rather than principal. A lump sum applied during that period reduces the balance at the point where the interest multiplier is highest — maximizing the reduction in both your monthly payment and your total interest cost.
Common sources of lump sums that work well for recasting: a tax refund, an annual bonus, the sale of another property, an inheritance, or simply savings accumulated over time. The key discipline is resisting the temptation to spend a windfall on depreciating assets and directing it instead to the balance where it produces a permanent, guaranteed return equal to your mortgage interest rate.
A recast is not ideal in every situation. If your goal is to pay off the loan as fast as possible and cash flow is not a concern, making extra principal payments without recasting shortens the loan term faster. If rates have dropped significantly and you plan to stay in the home long enough to recoup refinancing costs, a refinance may produce more total savings. The mortgage recast calculator above models your specific numbers so you can make the comparison with real data rather than general advice.
Frequently asked questions about mortgage recasting
What is a mortgage recast calculator?
A mortgage recast calculator shows you your new monthly payment after making a lump sum principal payment and requesting a recast from your servicer. You enter your current loan balance, interest rate, remaining term, lump sum amount, and recast fee. The calculator outputs your new monthly payment, monthly savings, total interest saved over the remaining loan term, and how many months until the recast fee pays for itself. The calculator on this page also includes a lender delay cost field — enter how many months your lender took beyond their stated timeline to see exactly what that friction cost you in unnecessary interest.
Why won’t my lender recast my mortgage?
Lenders are not required to offer mortgage recasting, and many servicers create friction around the process because a recast permanently reduces the interest revenue they collect from you each month. A refinance generates origination fees, appraisal costs, title insurance, and resets the amortization clock — all of which benefit the lender. A recast generates a $500 administrative fee and then reduces the lender’s interest income for the life of the loan. If your lender is slow, undertrained, or difficult about your recast request, it is not accidental. Escalate in writing, reference the CFPB complaint process, and be persistent. The transaction is straightforward — the friction is institutional, not technical.
Is biweekly mortgage payment worth it?
Biweekly mortgage payments are better than making only minimum monthly payments, but they are not the most efficient use of your money. The extra payment each year under a biweekly schedule eliminates months from the far end of your loan — payments in years 27, 28, and 29 that are already mostly principal by then. A more efficient strategy is to save the equivalent money in a high-yield savings account until you have a meaningful lump sum, then apply it to your principal during the years when your amortization is still heavily front-loaded, and request a recast. This produces a permanent reduction in your monthly payment and attacks the balance when the interest multiplier is highest — something a biweekly schedule cannot do. If your lender charges a setup fee for a biweekly program, do not pay it. You can make one extra principal payment per year yourself for free.
Mortgage recast vs. refinance — which is better?
A mortgage recast is better when your current interest rate is competitive and you want to lower your monthly payment without resetting your amortization clock or paying $8,000 to $15,000 in closing costs. A refinance is better when rates have dropped significantly and you plan to stay in the home long enough to recoup closing costs through the monthly savings — typically two to four years. The key disadvantage of refinancing that most people overlook is that a new 30-year loan resets your amortization schedule to month one, meaning you go back to paying mostly interest from the beginning. If you are already several years into your loan, a refinance can cost you more in total interest than staying with your current loan even at a slightly higher rate. Use the mortgage amortization truth page to see your current amortization position before deciding.
How long does a mortgage recast take?
Most servicers state a processing time of 30 to 60 days after receipt of the lump sum payment and recast request. In practice, the timeline varies significantly depending on the servicer. Some process recasts in two to three weeks. Others, particularly those that do not routinely handle recast requests, may take longer — sometimes due to institutional friction rather than genuine processing complexity. Get your expected timeline in writing, follow up in writing if the deadline passes, and escalate to a supervisor immediately if you experience delays beyond what you were promised. Every month of unnecessary delay costs you interest on the pre-recast balance.
What is the minimum lump sum for a mortgage recast?
The minimum lump sum required for a mortgage recast varies by servicer. Common minimums range from $5,000 to $10,000, though some lenders set higher thresholds. There is no universal federal requirement. Call your servicer and ask specifically: “What is the minimum lump sum required to qualify for a mortgage recast?” Get the answer confirmed in writing or by email. The recast fee — separate from the lump sum — typically runs $150 to $500 and is charged once for processing the re-amortization.
Can I recast my mortgage more than once?
Yes — most servicers that allow recasting permit multiple recasts over the life of the loan, though some impose a minimum waiting period between recasts, commonly 12 months. Each recast requires a new lump sum payment meeting the minimum threshold and a new recast fee. If you receive multiple windfalls over time — a bonus one year, a tax refund another — recasting each time compounds the benefit, with each successive recast attacking a progressively lower balance at whatever amortization stage you are in.
About the Author
James is a certified financial coach and the founder of DebtInterestCalculator.com. The mortgage recast described on this page is his own — $73,000 applied to a $360,000 loan, nine calls over three weeks, and one extra month of unnecessary interest paid while the lender processed it. He built this site to show people what the financial system does not voluntarily explain.
For educational purposes only. Does not constitute financial or legal advice. Consult a qualified professional before making mortgage decisions.
See what your current amortization looks like before you recast
The mortgage amortization truth page shows your year-one interest percentage, your crossover point, and how a lump sum changes your trajectory — the full picture your bank does not show you.