This West Virginia mortgage payoff calculator shows exactly how much interest you save and how many years you cut off your loan by paying a little extra principal each month — using full month-by-month amortization, not a rule of thumb.
How it works
First the tool computes your scheduled monthly principal-and-interest payment with the standard amortization formula:
M = P * r * (1 + r)^n / ((1 + r)^n - 1)where P is the loan, r is the monthly rate (annual / 12), and n is the number of months. It then runs two amortization schedules month by month:
- Baseline — only the scheduled payment.
- Accelerated — the scheduled payment plus your extra principal each month.
For each schedule it sums the interest paid and counts the months until the balance hits zero. The difference gives your months saved and total interest saved (baseline interest minus accelerated interest).
Example
A $320,000 West Virginia mortgage at 6.5% over 30 years has a scheduled payment of about $2,023/month and would cost roughly $408,142 in total interest.
Add just $200/month in extra principal and the loan pays off in about 23 years 5 months instead of 30 years — cutting off roughly 6 years 7 months and saving about $105,429 in interest.
Notes
This is an estimate only and not financial advice. It assumes a fixed interest rate, the same extra payment every month, and that your servicer applies extra funds to principal (confirm this — some apply extra to future payments instead). Property tax, insurance, and escrow are excluded. Check terms with your lender before committing to a prepayment plan.