Mortgage Recast Calculator
Got a lump sum? Recast, prepay, or refinance?
Loan type
$
%
$
$
%
$
Quick recommendation
Want a lower monthly payment? Pick Refinance ($1,850/mo).
Want the biggest net savings? Pick Extra payment (keep payment) ($158,630 saved after fees).
Best for cash flow
Refinance
$1,850/mo
Best for total savings
Extra payment (keep payment)
saves $158,630 net of fees
Lump sum
$50,000
14.7% of balance
Current monthly P&I
$2,261
26yr 0mo remaining
All four strategies side by side
Do nothing
Keep paying as scheduled. The lump sum stays liquid.
Monthly: $2,261Payoff: 26yr 0moTotal interest: $365,345
Pros
- +Cash stays liquid for emergencies / investments
Cons
- −No interest savings
Recast
Apply $50,000 to principal and re-amortize at the same rate. Lower monthly payment, same payoff date.
Monthly: $1,928Payoff: 26yr 0moTotal interest: $311,618Interest saved: $53,727 − $250 feenet savings $53,477Upfront: $50,250
Pros
- +Lowers monthly payment by $332
- +~$250 fee, way cheaper than refinancing
- +Same rate, same term, same lender. No requalification
Cons
- −Lump sum is locked in home equity (illiquid)
- −Less interest saved than the extra-payment route
Extra payment (keep payment)
Apply $50,000 to principal but keep paying $2,261/mo. Pay off earlier.
Monthly: $2,261Payoff: 18yr 4moTotal interest: $206,715net savings $158,630Upfront: $50,000
Pros
- +Interest saved: $158,630
- +Payoff 7yr 8mo earlier
- +No fees
Cons
- −Monthly payment unchanged, so no cash flow relief
- −Lump sum is locked in home equity
Refinance
New 5.875% rate, $5,500 closing rolled in.
Monthly: $1,850Payoff: 26yr 0moTotal interest: $281,625Interest saved: $83,720 − $5,500 closing costsnet savings $78,220
Pros
- +Lowers payment by $411
- +Lower lifetime cost, even after closing costs
Cons
- −$5,500 closing costs (rolled in here)
- −Requires requalification (credit, income, appraisal)
- −30–45 day process
- −Resets the loan. May extend term if you stretch back to 30 years
What is a recast? You hand the lender a lump sum and pay a small fee (typically $150–$500). They re-amortize your loan: same rate, same payoff date, lower monthly payment. It’s the simplest way to get the cash-flow benefit of a refinance without the cost or hassle. Most conventional loans allow it; ask your servicer.