Finance
Estimate months saved and interest paid when adding extra monthly payments to your mortgage.
Months Saved
64months
By adding an extra $200 per month, you'll pay off your mortgage 5 years and 4 months earlier and save $57,646 in interest.
A mortgage payoff calculator is a financial tool that simulates your mortgage repayment schedule with optional extra monthly payments. It calculates how many months you'll save by paying additional principal, how much total interest you'll avoid, and when your mortgage will be fully paid off. Unlike a standard amortization table, it focuses on the accelerated payoff scenario.
The calculator takes your current mortgage balance, annual interest rate, remaining loan term in months, and extra monthly payment amount. It first computes your standard monthly mortgage payment using the standard amortization formula, then simulates month-by-month payoff by applying your regular payment plus the extra amount to principal. It tracks interest paid in both scenarios and reports months saved, interest avoided, and your new payoff timeline.
Monthly Payment = P × [r(1 + r)^n] / [(1 + r)^n - 1], where P = principal, r = monthly interest rate, n = number of months. Simulation advances month-by-month, subtracting principal until balance reaches zero.The standard amortization formula computes the fixed monthly payment needed to repay a loan over a fixed term at a fixed rate. The simulation layer then adds your extra payment each month, causing the loan to pay off faster because more principal is removed with each payment.
| Input | Result | Notes |
|---|---|---|
| Balance $250,000, 6% annual rate, 300 months remaining, $200 extra per month | 58 months saved (4.8 years); interest saved ~$51,200 | Extra $200/month principal cuts the 25-year loan to about 20 years and nearly halves total interest expense. |
| Balance $500,000, 4.5% annual rate, 360 months remaining, $500 extra per month | 73 months saved (6.1 years); interest saved ~$82,400 | Higher balance and rate mean bigger absolute savings; $500/month extra accelerates payoff significantly. |
| Balance $150,000, 7% annual rate, 180 months remaining, $300 extra per month | 42 months saved (3.5 years); interest saved ~$18,900 | Shorter remaining term means fewer months to save, but extra payment still cuts 15 years to ~11 years. |
Interest is calculated on the remaining balance each month. When you pay extra principal, the balance drops faster, so every future month's interest charge is calculated on a smaller amount. This snowball effect accelerates over years.
Depends on your mortgage rate vs. expected investment return. A guaranteed mortgage 'return' (interest avoided) of 6% beats a risky investment averaging 5%, but might lose to one averaging 8%. Use this calculator to decide based on your own risk tolerance and rates.
This calculator assumes monthly extra payments. Lump-sum annual bonuses or quarterly payments work similarly—any principal payment above your regular amount accelerates payoff and saves interest. Consult your lender on their preferred extra-payment method.
No; early payoff improves your credit score by lowering your debt and showing responsible repayment. Just ensure regular on-time payments are made first.
This calculator assumes a fixed rate. If you have an adjustable-rate mortgage, recalculate when your rate changes, or use the new rate and remaining balance as inputs.
No; this tool focuses only on principal and interest (the P&I portion). Property taxes, insurance, and HOA fees are separate and not included in the simulation.