Mortgage Payoff Calculator
Compare up to three monthly extra-principal plans with a modeled baseline, or work backward from a target payoff month.
Advanced: next payment month
Extra principal begins with this modeled payment month.
How to use the mortgage payoff calculator
Enter the current principal balance from your statement, the fixed annual interest or note rate, the remaining term in months, and the next payment month. The rate field is for the note rate, not APR. The calculator derives a modeled monthly principal-and-interest payment, then compares up to three monthly extra-principal amounts with that baseline.
For a deadline-first estimate, select a target payoff month. The solver finds the minimum modeled monthly extra principal, rounds it up to the next cent, and checks that rounded amount against the same schedule.
What this fixed-rate monthly model calculates
For each month, the estimate calculates interest from the current principal balance and one-twelfth of the annual note rate. The rest of the scheduled principal-and-interest payment, plus the selected extra amount, reduces principal. That process repeats until the balance reaches zero; the final modeled payment can be smaller than a normal payment.
The baseline and three plans use the same balance, rate, remaining term, derived scheduled payment, and next payment month. Comparing them on one aligned schedule makes the estimated payoff month, months saved, and interest saved easier to audit. This derived baseline can differ from the payment on your statement, especially if prior extra-principal payments did not trigger a recast.
Annual interest rate is not APR
Use the annual interest rate shown for the loan, often called the note rate. The CFPB explains that APR is a broader measure that combines the interest rate with points, fees, and other charges. Entering APR here would treat those other costs as if they were the loan's monthly interest rate and would not match this model.
Estimate, not a lender payoff quote
This calculator is an estimated fixed-rate monthly model. It is not a payoff statement or quote from a lender or mortgage servicer. A lender payoff amount can include interest through a specific payoff date, unpaid fees, and a prepayment penalty, so it can differ from the current principal balance and from this estimate.
Extra amounts are assumed to be applied to principal with each monthly payment, beginning in the next payment month. A servicer's actual posting date, rounding rules, and treatment of additional funds can change the result.
Payment and loan boundaries
The derived scheduled payment is principal and interest only. The model excludes property tax, homeowners insurance, mortgage insurance or PMI, escrow, HOA dues, lender fees, late fees, and prepayment penalties. It does not calculate an all-in housing payment.
The calculator covers a current fixed-rate, fully amortizing mortgage with a constant monthly principal-and-interest payment. It does not model adjustable-rate mortgages, refinancing, mortgage recasting, interest-only periods, balloon payments, delinquent or modified loans, taxes, rate shopping, or financial advice.
Frequently asked questions
How do extra principal payments change a mortgage payoff?
Each modeled monthly extra payment reduces principal after the scheduled principal-and-interest payment. That leaves a smaller balance for later monthly interest calculations, which can shorten the payoff period and reduce estimated interest.
Which mortgage rate should I enter?
Enter the annual interest rate, also called the note rate, for the current fixed-rate loan. Do not enter APR. The CFPB explains that APR is a broader cost measure that includes the interest rate plus points, fees, and other charges.
Does the calculated monthly payment include taxes or insurance?
No. The calculator derives a scheduled monthly principal-and-interest payment from the current principal, note rate, and remaining term. It excludes property tax, homeowners insurance, mortgage insurance or PMI, escrow, HOA dues, fees, and any prepayment penalty.
How does the target payoff month calculation work?
The calculator searches for the minimum additional monthly principal that would pay the modeled balance by the selected month, rounds that amount up to the next cent, and verifies the rounded amount against the same monthly schedule.
Why could my lender's payoff amount be different?
This is a monthly estimate, not a lender payoff quote. The CFPB notes that a payoff amount can include interest through the payoff date, unpaid fees, and a prepayment penalty. Payment timing, lender rounding, and principal-posting rules can also change the result.
Can I use this for an ARM, refinance, or mortgage recast?
No. The calculator models a current fixed-rate mortgage with a constant note rate and monthly principal-and-interest payment. It does not model adjustable rates, refinancing, recasting, interest-only periods, balloon payments, taxes, insurance, or loan advice.
Sources and method
- CFPB — How does paying down a mortgage work?
- CFPB — Mortgage interest rate compared with APR
- CFPB — Payoff amount compared with current balance
- CFPB — Principal and interest compared with total monthly payment
- CFPB — Mortgage servicer rules and extra payments
- Fannie Mae — Homebuyer frequently asked questions