Mortgage Payoff Calculator with Lump-Sum Payment
Model a one-time principal payment and compare before/after payoff timelines and interest costs.
Why this page
Planning a bonus or windfall payment? Use this page to simulate a single lump-sum principal payment and its payoff impact.
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Loan Inputs
Results
Extra Payment Impact
Estimate Disclaimer
Estimates only. Results are based on your inputs and may not reflect final loan terms, taxes, insurance, HOA dues, PMI rules, lender fees, or escrow adjustments. Confirm final numbers with your lender, servicer, and local tax/insurance sources before making financial decisions.
Amortization Table
| Month | Rate % | Begin Bal | Interest | Principal | Extra | PMI | PITI Outflow | End Bal |
|---|
Assumptions
- Estimate only. Excludes escrow shortages, lender fees, and refinance costs.
- For adjustable rate, future rates are user-entered assumptions.
- PMI uses original home value and stops when LTV reaches chosen threshold (default 78%).
Publisher Status
We are an informational publisher, not a mortgage lender, broker, or loan servicer.
FAQ
Is a lump-sum payment applied to principal?
Typically yes when designated as principal-only; confirm processing with your servicer.
When is best time to make a lump-sum payment?
Earlier principal reduction usually creates larger interest savings.
Lump sum vs monthly extra: which saves more?
At equal total dollars, earlier application of principal often saves more interest.
Can I model multiple lump sums?
Yes, by testing separate scenarios and comparing payoff dates and total interest.