Mortgage Recast Calculator
Pay a lump sum, keep your rate, and see how far your monthly payment drops.
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A mortgage recast re-amortizes your loan after you pay a lump sum, at the same rate and with the same payoff date. On a $300,000 balance at 6.5% with 27 years left, paying $50,000 and recasting lowers the payment from $1,967 to $1,639 — $328 less each month. Lenders typically charge $150–$500.
Lenders often ask for $5,000–$10,000 minimum.
Typically $150–$500.
New monthly payment
$1,639
- Payment before recast
- $1,967
- Monthly saving
- $328
- Interest saved over the loan
- $56,200
- Net saving after fee
- $55,950
- Months for the fee to pay back
- 1
Principal and interest only. Same rate and same payoff date — a recast lowers the payment, not the term.
New payment after recasting a $300,000 balance at 6.5%, 27 years left
| Lump sum | New payment | Monthly saving | Interest saved |
|---|---|---|---|
| $10,000 | $1,901 | $66 | $11,240 |
| $25,000 | $1,803 | $164 | $28,100 |
| $50,000 | $1,639 | $328 | $56,200 |
| $75,000 | $1,475 | $492 | $84,300 |
| $100,000 | $1,311 | $656 | $112,400 |
How it works
When you recast a mortgage, you pay a large amount toward principal and the lender recalculates your monthly payment on the lower balance over the months you have left. The interest rate and the end date stay the same; only the payment changes. It is sometimes called re-amortization.
A recast is not a refinance. There is no new loan, no credit check, no appraisal and no closing costs — just a small administrative fee. That makes it useful when you have a lump sum (from a bonus, an inheritance or the sale of a previous home) but already have a good interest rate you do not want to give up. If current rates are well below yours, refinancing may save more.
Recasting and extra mortgage payments reduce the same balance in different ways. Extra payments keep the payment the same and finish the loan sooner, saving more total interest. A recast keeps the same end date and frees up cash every month. Most conventional loans can be recast; FHA, VA and USDA loans generally cannot.
Start with your current balance and the years remaining from your latest statement. To compare against a brand-new loan, run the numbers in the mortgage calculator. If a lump sum also takes your balance below 80% of the home's original value, you may be able to remove PMI at the same time.
More mortgages & home loans calculators
- Mortgage CalculatorSee your full monthly house payment — not just principal and interest — and how much interest you pay over the loan.
- Mortgage Extra Payment CalculatorFind out what paying a little extra each month really saves — in dollars and in years.
- PMI Removal CalculatorWork out exactly when you can stop paying private mortgage insurance — and how to get there sooner.
Frequently asked questions
What is the minimum lump sum to recast a mortgage?
It varies by lender, commonly $5,000 to $10,000, or a percentage of the balance. Ask your servicer for its rules and fee.
Does a recast lower my interest rate?
No. The rate stays the same. Only the monthly payment drops because it is calculated on a smaller balance.
Recast or refinance — which is better?
Recast if you like your current rate and want a lower payment cheaply. Refinance if market rates are meaningfully lower than yours and you will stay long enough to recover the closing costs.
Can I recast an FHA or VA loan?
Usually not. Government-backed FHA, VA and USDA loans generally do not allow recasting; conventional loans usually do.