Monthly Payment
Calculate the fixed payment for a fully amortizing loan. payment = balance × (rate/12) / (1 − (1 + rate/12)^(−remainingMonths))
Finance
About Mortgage Payoff Calculator
See how extra payments, biweekly schedules, and payoff quotes reshape your loan's timeline and total cost.
About this calculator
What this does
Calculates how extra payments, biweekly payment schedules, and lump-sum contributions affect your mortgage payoff date and total interest paid. It compares your current loan path against an accelerated payoff scenario and shows the interest savings and time saved.
Who it is for
Homeowners who want to pay off their mortgage earlier by making extra principal payments or switching to a biweekly payment schedule. Also useful for anyone comparing the long-term cost of different payoff strategies.
How it works
The calculator uses a fixed-rate monthly amortization formula. Your loan balance earns interest each period, and your payment first covers that interest before reducing the principal. Extra payments go directly toward principal reduction, shortening the remaining term and lowering total interest.
Limitations
Assumes a fixed interest rate for the life of the loan. Does not handle adjustable-rate mortgages (ARMs), escrow changes, PMI removal dates, or lender-specific payoff quote calculations. Biweekly savings are modeled as the equivalent of one extra monthly payment per year.
Formula
Interest for a Period
The portion of a payment that goes toward interest. interest = outstandingBalance × (annualRate / 12)
Principal Reduction
The remainder of the payment after covering interest. principal = payment − interest, which grows each month as the balance shrinks.
Payoff Quote
The total needed to close the loan including per-diem interest. payoffQuote = principalBalance + perDiemInterest × daysSinceLastPayment
How it works
Step 1
Enter your loan details
Input your current mortgage balance, interest rate, remaining term in months, and monthly payment amount.
Step 2
Set your payoff quote date
Enter the date you want a payoff quote for. The calculator adds per-diem interest from your last payment date to that quote date.
Step 3
Add extra payments
Enter an extra monthly principal payment, a biweekly schedule option, or a one-time lump sum to accelerate your payoff.
Step 4
Compare baseline vs accelerated
The calculator shows two columns: your current loan path and the accelerated path with extra payments. Compare payoff dates and total interest side by side.
Step 5
Review the amortization table
Scroll through the full payment schedule to see how each payment is split between principal and interest over the life of the loan.
Reference ranges
Extra Payment Amount
Even an extra $50–$100 per month can shorten a 30-year mortgage by several years. A common target is one extra full payment per year, often achieved through a biweekly schedule.
Interest Rate Impact
Rates below 4% make extra payments less compelling if you can invest the difference. Rates above 6% make early payoff more attractive as a guaranteed return.
Payoff Timeline
A 30-year loan with no extra payments runs the full term. Adding $200/month on a $300,000 loan at 6% can shorten the term by 8–10 years and save over $100,000 in interest.