Free tools / Recast mortgage calculator
Recast Mortgage Calculator
See your new monthly payment after a lump-sum principal payment — plus the interest you'd save, when the recast fee pays for itself, and how recasting stacks up against simply prepaying. Free, no signup.
Your current loan
From your latest mortgage statement
Decimals OK — 26.5 = 26 years 6 months
The recast
Most lenders require at least $5,000–$10,000
Typically $150–$500, set by your servicer
A recast keeps your rate and payoff date — the lender simply re-amortizes the smaller balance over the remaining term, so the monthly payment drops.
New monthly payment
$1,795
$332/month lower (was $2,128)
The $250 fee pays for itself in 1 month.
The math
- Balance today
- $320,000
- Lump-sum payment
- −$50,000
- Re-amortized balance
- $270,000
- Over the same 26 years at 6.5%
- $1,795/mo
- Interest saved vs. no recast
- $53,727
Same lump sum, no recast?
If you made the $50,000 payment but kept paying $2,128/mo, you'd pay the loan off 8 yr 1 mo early and save $155,906 in interest — more than the recast's $53,727.
Recast when you want a lower required payment (cash-flow flexibility); skip the recast when your goal is paying the least total interest.
How to use the recast calculator, step by step
- 1
Enter your remaining loan balance
How much you still owe on the mortgage — not the original loan amount. It's on your latest statement or in your lender's app, usually labeled "principal balance."
- 2
Enter your interest rate and years remaining
Both are on the same statement. For years remaining, decimals work — if you have 26 years and 6 months left, enter 26.5.
- 3
Enter the lump sum you're considering
The one-time amount you'd put toward the loan — proceeds from selling a previous home, a bonus, an inheritance. Most lenders require at least $5,000–$10,000 for a recast.
- 4
Enter the recast fee
A one-time charge from the company that collects your mortgage payment (your loan servicer) — typically $150 to $500. One phone call to them gets you the exact number, and whether your loan qualifies at all.
- 5
Compare your two options
The green box shows your new, lower monthly payment and how fast the fee pays for itself. Below it, the "same lump sum, no recast" box shows the alternative: keep your old payment and pay the loan off years early instead. Lower monthly bills or less total interest — the two boxes show exactly what each path costs.
What is mortgage recasting?
Recasting (also called re-amortization) is the quiet alternative to refinancing. You make a large one-time payment toward principal, pay a small servicing fee, and your lender recalculates your monthly payment on the smaller balance — same interest rate, same payoff date, lower required payment.
New payment = re-amortize (balance − lump sum) over the remaining term at your existing rate
No credit check, no appraisal, no closing costs — just a servicing fee, typically $150–$500.
Recast vs. refinance vs. just prepaying
Say a chunk of money lands in your lap and you want to put it toward the house. You actually have three options, and they lead to very different places.
Recasting means you hand your lender the money, pay a small one-time fee, and they recalculate your monthly payment based on the smaller amount you now owe. Your interest rate doesn't change and the loan still ends on the same date — the only thing that changes is your monthly bill, which gets permanently smaller. Pick this when what you want is breathing room in the monthly budget.
Refinancing means replacing your entire loan with a brand-new one at today's rates. That only helps if today's rates are lower than what you're paying — and it costs real money (typically 2–5% of the loan in closing costs) plus a credit check and paperwork. If you locked in a low rate years ago, refinancing means giving that rate up.
Just prepaying means putting the money toward the loan and changing nothing else. Your monthly payment stays exactly the same — but because you owe less, more of each payment chips away at the balance, and the loan ends years ahead of schedule. It costs nothing, and of the three options it saves the most interest overall. Pick this when your goal is being done with the mortgage, not lowering the bill.
Here's the same comparison at a glance:
| Recast | Refinance | Prepay only | |
|---|---|---|---|
| Monthly payment | Drops | Depends on new rate/term | Unchanged |
| Interest rate | Keeps your current rate | New market rate | Keeps your current rate |
| Payoff date | Unchanged | Resets to new term | Moves earlier |
| Cost | $150–$500 fee | 2–5% closing costs | Free |
| Best for | Lower fixed costs, keeping a low rate | When rates dropped below yours | Minimizing total interest paid |
The calculator above shows the recast and prepay-only paths on your actual numbers, so you can see the trade-off — lower payment now versus more interest saved overall — before you call your servicer.
The fine print to check before you call
Recasting happens through your loan servicer — the company you send your mortgage payment to. Their rules vary, so ask about these four things:
- Eligibility: conventional and most jumbo loans qualify; FHA, VA, and USDA loans generally can't be recast.
- Minimum lump sum: commonly $5,000–$10,000, sometimes a percentage of the balance.
- Timing: the new payment usually takes effect one to two statement cycles after the lump sum posts.
- Escrow: taxes and insurance don't change — only the principal-and-interest portion of your payment drops.
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Mortgage recasting FAQs
What is mortgage recasting?
Recasting is when you make a large lump-sum payment toward your mortgage principal and your lender re-amortizes the smaller balance over your remaining term at your existing rate. Your monthly payment drops; your rate and payoff date stay the same. It usually costs a small fee ($150–$500) and requires a minimum lump sum, often $5,000–$10,000.
What's the difference between recasting and refinancing?
A refinance replaces your loan: new rate, new term, closing costs (typically 2–5% of the loan), a credit check, and full underwriting. A recast keeps your existing loan and rate — the lender just recalculates the payment on the smaller balance for a small fee, with no credit check or appraisal. If you have a low locked-in rate, recasting lowers your payment without giving that rate up.
Does recasting shorten my loan term?
No — that's the defining trade-off. Recasting keeps your payoff date and lowers the required monthly payment. If your goal is paying the loan off early and minimizing total interest, make the same lump-sum payment WITHOUT recasting and keep paying your old amount: the term shortens and you save more interest. The calculator shows both paths side by side.
Can any mortgage be recast?
Most conventional loans (Fannie Mae / Freddie Mac) and many jumbo loans can be recast. Government-backed loans generally cannot — FHA, VA, and USDA loans don't offer recasting. Policies vary by servicer, so call yours and ask about their minimum lump sum and fee.
How much does it cost to recast a mortgage?
Typically a flat servicing fee of $150–$500 — dramatically cheaper than refinancing. Because the fee is small, the payment savings usually cover it within the first month or two.
When does recasting make the most sense?
When you receive a windfall — home-sale proceeds, a bonus, an inheritance — and you want lower fixed monthly costs while keeping a below-market interest rate. It's common for buyers who purchase a new home before selling the old one: recast with the sale proceeds afterward, and the payment drops to what it would have been with a bigger down payment.