15-Year Mortgage Recast Calculator
Payment breakdown
Interest & break-even
Total monthly housing cost
Where your money goes over time
If the freed-up cash is invested at 7%, the saved payments grow to about $0 by payoff.
Four ways to use that cash
| Scenario | Monthly P&I | Interest left | Payoff | What happens |
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Show the full amortization schedule (before vs after)
| # | Int. now | Prin. now | Bal. now | Int. recast | Prin. recast | Bal. recast |
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How to use this calculator
- Enter your current loan balance, interest rate, and remaining term.
- Enter the lump-sum amount you plan to pay toward principal.
- Click Calculate to see your new payment, interest savings, and comparison.
About this tool
Recasting a 15-year mortgage behaves differently than a 30-year one. With fewer payments left and more of each going to principal, a lump sum has a distinct effect on both your monthly bill and your total interest. Set the term to 15 years below and see it on your numbers.
Why recasting a 15-year loan feels different
On a 15-year mortgage, you're already on an aggressive payoff schedule, so two things stand out when you recast. First, the monthly payment reduction per dollar of principal tends to be smaller than on a 30-year loan, because the payment is spread over fewer months to begin with. Second, because a 15-year loan front-loads principal, your interest savings from a recast can still be meaningful even though the payment moves less dramatically.
That combination changes the calculus. If your goal is cash-flow relief, a recast on a 15-year loan gives you less per dollar than the same payment on a 30-year loan. If your goal is to be debt-free even faster, the "pay down and keep paying" path — shown in the comparison table — is often the standout, clearing an already-short loan years ahead of schedule.
Recast vs. just paying it down on a 15-year loan
Because a 15-year mortgage already carries a higher monthly payment, many borrowers who recast do it specifically to ease that payment. But run both options: keeping the higher payment on a reduced balance can retire the loan strikingly early. The calculator quantifies each path, and projects what the freed-up money would become if invested instead — a comparison that matters more on short loans, where the remaining interest to save is smaller.
Considering a 30-year instead?
Weighing a refinance to a different term? See how recast and refinance stack up.
On a longer loan, see the 30-year recast calculator instead.
Who a 15-year recast really suits
A 15-year mortgage attracts disciplined borrowers who wanted to be debt-free quickly and accepted a bigger payment to get there. That profile shapes when a recast helps and when it doesn't.
If life shifted — a career change, a new baby, a business that needs air — and the aggressive payment now pinches, a recast is a graceful fix. You keep the short timeline and the low 15-year rate but ease the monthly load using cash you already hold. No refinance to a longer term, no rate bump, no restart.
If your income is steady and speed is still the goal, pause before recasting. On a loan this short, keeping the original payment on a reduced balance can retire the mortgage strikingly early and save the most interest. Recasting trades some of that acceleration for monthly comfort. Neither choice is wrong — the comparison table above shows the exact figures so you decide on purpose rather than by default.
A note on break-even
Because the fee is small and a 15-year payment is already large, fee break-even is usually a single billing cycle. The real "cost" of recasting a short loan isn't the fee — it's the interest you give up by not keeping the higher payment.
15-year recast questions
Refinance from 30 to 15 years, or recast?
Different tools. Refinancing to 15 years changes your rate and shortens the term but brings closing costs and underwriting. A recast keeps your existing loan and only lowers the payment. If today's 15-year rate beats yours, compare both.
Does a 15-year recast reset me to a fresh 15 years?
No. A recast never extends your term. You keep the years you have left; only the payment is recalculated on the smaller balance.
Is the lump-sum minimum different on a 15-year loan?
The minimum is set by your servicer, not the term. It's commonly in the $5,000–$10,000 range whether the loan is 15 or 30 years. Confirm the current figure with yours.
Can you recast a 15-year mortgage?
Yes, if your loan and servicer allow it — the term doesn't disqualify you. Most conventional 15-year fixed loans are eligible; confirm with your servicer.
Does recasting a 15-year loan save much?
The monthly payment drops less per dollar than on a 30-year loan, but interest savings can still be solid because 15-year loans pay down principal quickly. Run your figures to see.
Is it better to recast or pay down a 15-year loan?
If you want lower payments, recast. If you want to be debt-free even sooner, keep the payment the same on the reduced balance. The comparison table shows both outcomes.
Does the payoff date change?
No — a recast keeps your existing payoff date and lowers the payment. To finish earlier, don't recast; keep paying the original amount.