This mortgage recast calculator shows your new monthly payment if you make a lump-sum payment and ask your lender to recast your mortgage. It also compares recasting with simply paying the lump sum and keeping your current payment.
What is a mortgage recast?
A recast (or re-amortization) is when you pay down a large amount of principal and the lender recalculates your monthly payment over the remaining term. The interest rate and end date stay the same, but the payment drops. Lenders usually charge a small fee and require a minimum lump sum.
Recast vs refinance vs extra payments
| Option | Payment | Rate | Cost |
|---|---|---|---|
| Recast | Lower | Same | Small fee |
| Refinance | Can be lower | New rate | Closing costs |
| Lump sum, keep payment | Same | Same | None; loan ends sooner |
Worked example
With $300,000 left at 6.5% and 25 years to go, the payment is $2,025.62. After a $50,000 lump sum and recast, it drops to $1,688.02, saving $337.60 a month. Keeping the old payment instead would pay the loan off nearly 8 years sooner and save more interest.
When recasting makes sense
Recasting suits people who receive a large sum, such as from selling a previous home, and want a lower payment without giving up a low interest rate.
Frequently asked questions
How much does a mortgage recast cost?
Usually a few hundred dollars. Many lenders also require a minimum lump sum, often $5,000 to $10,000 or more.
Can every mortgage be recast?
No. Conventional loans often can, but FHA, VA and USDA loans generally cannot. Ask your servicer.
Does recasting save interest?
Yes, because the lump sum lowers the balance that interest is charged on. Keeping your old payment saves even more by ending the loan sooner.
Does a recast affect my credit?
No. It is not a new loan, so there is no credit check or new account.
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Sources
Last reviewed: October 2026. For information only; not financial, tax or legal advice.