Financing · United States
Mortgage Recast Calculator
See what a lump sum does to your monthly payment — and what that choice costs you against simply paying the same money in and leaving your payment alone.
Your loan
- Payment today
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- Balance after lump sum
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The same lump sum, two ways
Recast
Lower payment
- Monthly payment
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- Paid off in
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- Total interest
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Keep paying the same
Less interest
- Monthly payment
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- Paid off in
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- Total interest
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This is an estimate
These figures cover principal and interest only — your actual bill also carries escrow for taxes and insurance, which a recast does not change. Servicer fees, minimum lump sums and eligibility all vary. Confirm the numbers with your servicer before moving money. Nothing here is financial or legal advice.
The detail
Recasting buys cash flow, not savings
This is the part most recast calculators leave out. Putting a lump sum against your principal saves you interest either way — but recasting saves youless of it than doing nothing else at all.
The reason is straightforward once you see it. If you hand over the money and keep paying what you pay now, every dollar above the newly-reduced interest goes to principal, and the loan collapses years ahead of schedule. If you recast, the lender stretches that smaller balance back across the full remaining term, so you pay less each month but you pay for longer. The lump sum is the same. What differs is whether you spend the benefit on monthly breathing room or on finishing early.
Neither is wrong. If a lower payment is what makes your budget work — a new baby, a single income, a move to part-time — that flexibility is worth real money, and a recast delivers it for a few hundred dollars in fees rather than the several thousand a refinance would cost. Just make the trade knowingly.
Before you call your servicer
What to know about recasting
What a recast actually does
You pay a lump sum against principal, and your lender re-amortises the remaining balance across the term you have left, at the rate you already have. The result is a smaller monthly payment. Your rate does not change, your payoff date does not change, and you do not requalify — there is no credit check, no appraisal, and no closing costs beyond a modest processing fee.
How it differs from a refinance
A refinance replaces your loan. You get a new rate, a new term, and a new set of closing costs, and you have to qualify all over again. That makes refinancing the right move when rates have fallen far enough to pay back those costs. A recast changes nothing about the loan except the size of the payment, which makes it the cheaper option when your rate is already competitive and what you actually want is breathing room in the monthly budget.
How it differs from just paying extra
Paying a lump sum without recasting leaves your payment exactly where it is. Because more of each payment then goes to principal, the loan clears years earlier and you pay far less interest overall. Recasting takes the same lump sum and spends the benefit on a lower payment instead. Both are reasonable; they simply buy different things, and the calculator above shows what each one costs.
Which loans are eligible
Recasting is generally available on conventional loans held or backed by Fannie Mae and Freddie Mac. Government-backed loans — FHA, VA and USDA — generally cannot be recast, though refinancing into a conventional loan first is sometimes a route. Jumbo loans vary by lender. Nothing obliges a servicer to offer recasting at all, so confirm before you commit the money.
The fee and the minimum
Servicers typically charge a flat processing fee, often somewhere between $150 and $500, and set a minimum lump sum before they will recast. Some also cap how many times you may do it over the life of the loan. These are servicer policies rather than regulations, so they vary — ask yours directly rather than relying on a figure you read anywhere, including here.
How to ask for one
Contact your servicer and ask specifically for a recast, or re-amortisation. Confusion with refinancing is common on both sides of that call, so be explicit that you are not seeking a new loan. Expect to send the lump sum and a written request, and allow a billing cycle or two before the lower payment takes effect. Keep paying the old amount until they confirm in writing.