Mortgage Payoff Calculator
See exactly how many years and how much interest you'll save by adding to your mortgage — with monthly, annual, one-time, and biweekly extras, plus an opportunity-cost check against investing.
- 30yr Fixed6.51%
- 15yr Fixed5.84%
- 5/1 ARM6.47%
- 2yr Fixed5.68%
- 5yr Fixed5.63%
- Tracker3.96%
- Variable6.20%
- 2yr Fixed5.90%
- 5yr Fixed5.54%
- Variable5.95%
Rates shown are national averages for reference only. Actual rates vary by lender, credit score, and LTV. US 30/15-yr figures auto-refresh daily from the Freddie Mac PMMS public dataset.
Inputs
How it works
We simulate both amortization schedules month-by-month:
- Baseline: your scheduled P&I payment for the full term.
- Accelerated: scheduled P&I + extra monthly + annual extras + one-time lump sum + biweekly (if enabled).
Interest saved = baseline total interest − accelerated total interest. Time saved = baseline months − accelerated months. The opportunity-cost box grows your extra dollars at your chosen investment return so you can compare the two strategies apples-to-apples.
Frequently asked questions
How do extra principal payments work?
Every dollar above your scheduled payment reduces the loan balance directly. Because interest is charged on the remaining balance, cutting principal early saves compounded interest for the whole remaining term.
Are biweekly payments really that powerful?
Paying half your monthly amount every two weeks results in 26 half-payments = 13 full payments per year — one extra. That alone typically cuts a 30-year loan by 4–6 years.
Should I pay off the mortgage or invest?
Compare your after-tax mortgage rate to your expected after-tax investment return. If investing wins by a comfortable margin AND you have emergency savings, invest. Otherwise the guaranteed return of paying down debt is hard to beat risk-adjusted.
Will my lender apply extras to principal?
Almost always yes for conforming loans, but note it explicitly ("apply to principal") on the payment or check. Some servicers otherwise prepay future payments instead.
Are there prepayment penalties?
Rare on modern conforming mortgages, but check your note. Some non-QM and older loans still have soft-prepay clauses.
Does paying extra lower my monthly payment?
No — it shortens the loan. Your required monthly stays the same until you request a recast (usually after a lump sum) which re-amortizes the lower balance over the remaining term.