Independent calculation workspace
Mortgage Recast Calculator
See how a lump-sum payment lowers your monthly mortgage payment when you recast
- No signup
- No lender matching
- Runs in your browser
- Replace defaults with your quote
Your Mortgage
Your remaining mortgage balance
Your current rate — unchanged by a recast
Years left on your mortgage
Recast Details
Principal you'll pay before recasting
Lender fee to recast (often $150–$500)
Before vs. After Recast
Current Loan
After Recast
Your savings
Recast Summary
Tip: a recast lowers your required payment but keeps the same payoff date. If your goal is to be mortgage-free sooner, paying the lump sum without recasting (and keeping your current payment) saves more interest. Estimates only — confirm recast eligibility, minimums, and fees with your servicer.
Use the tool
How to use this Mortgage Recast Calculator
Enter your current balance, interest rate, and remaining term, then the lump sum you plan to pay and any recast fee. The calculator shows your new payment, monthly savings, and interest saved.
How the mortgage recast estimate works
Recasting re-amortizes your loan after a principal payment. The rate and remaining term stay the same, so the only thing that changes is a lower monthly payment. Planning to buy your next home? Check affordability on PlainSums.
Before you compare offers
If your goal is to pay the loan off faster, making the lump-sum payment without recasting (keeping your current payment) saves more interest. Recast when you want a lower required payment while keeping your low rate.
Frequently Asked Questions
A recast applies a lump-sum payment to your principal, then re-amortizes the loan over the remaining term — lowering your monthly payment while keeping the same rate and payoff date. Most lenders charge a small fee (often $150–$500).