Mortgage Payoff & Amortization Forecast
Build a full annual mortgage schedule and compare monthly extra principal or a 13-payment budget spread monthly. See payoff, interest and actual final cash.
What This Calculator Does
Forecast a fixed-rate loan from the entered starting principal over the selected full term. The model accrues monthly interest and applies scheduled P&I with any extra principal at each month-end payment. The 13-payment option is explicitly a monthly-equivalent annual-budget approximation, not a real biweekly posting schedule. Read the complete financial summary and annual schedule through payoff.
Who Is This For
Borrowers comparing theoretical monthly principal-and-interest schedules in U.S. dollars, including the effect of extra principal. Existing borrowers need compatible balance and remaining-term facts; the model does not reconstruct their payment history.
How It Works
Enter principal and fixed nominal annual rate, choose the full term and payment method, and confirm the monthly convention. In extra-monthly mode, enter an explicit amount, even 0. Do not treat blank fields or examples as confirmed loan terms. Review planned versus actual final cash, no-extra savings and all annual rows; verify actual posting and payoff instructions separately.
Frequently Asked Questions
What does this forecast calculate?
Scheduled monthly principal and interest, the selected extra budget, planned monthly cash, payoff month, actual final payment, total interest and payments, no-extra savings and extra principal actually applied. All annual rows run through payoff. It starts from the entered debt for the full selected term; it does not infer elapsed payments, current statement balances, fees or loan approval.
Is the 13-payment option an exact biweekly schedule?
No. It adds scheduled monthly P&I divided by 12 as extra principal at each monthly payment. The annual budget matches 13 scheduled monthly payments; the arithmetic of 26 half-payments also gives 13. That does not establish actual 14-day dates, partial-payment crediting or daily interest. The same annual extra paid at year-end can produce a different payoff and interest result.
Does the scheduled monthly payment include extra principal?
No. Scheduled P&I is separate from the requested or derived extra budget. Planned monthly cash adds them. The forecast applies them together at month-end, but the final payment can use less. A monthly-equivalent extra can contain fractions of cents because the forecast does not round intermediate values.
Can extra principal overpay the loan in the final month?
The model caps actual cash at the principal still owed plus that month’s interest and then stops. It does not count unused budget as paid. Total extra actually applied counts only used cash above scheduled P&I, not requested extra multiplied by the number of payments. Annual principal already includes used extra; do not add it again.
Why might this differ from a bank’s amortization statement?
This theoretical forecast retains unrounded monthly payments, balances and interest and rounds only the display. A bank can use cent-rounded charges, different dates or partial-payment rules. Positive modeled debt is not forgiven just because it is below half a cent. Displayed cents are not a promise about actual billing; request the servicer’s payoff quote to close the loan.
Are zero rates and zero extra allowed?
An explicit 0% rate is a valid hypothetical calculation, not an available loan offer. Extra-monthly mode accepts an explicit $0 and then matches the no-extra baseline. Blank is unknown, not 0. Standard and monthly-equivalent modes do not use a hidden user extra. The public term selector offers 10, 15, 20, 25 and 30 years; those options are not lender eligibility rules.
What do interest saved and the annual schedule include?
Savings compare the same starting principal, rate and term with no extra. They are nominal modeled interest and months, not investment return or a lowest-total-cost decision. Annual principal includes extra, interest is separate, and the final partial year is retained. Read the full annual schedule in the result and PDF. The AI briefing uses the complete 11-metric financial summary, not every annual row.
What should I confirm with the servicer?
Confirm the note rate, starting debt, term, allocation of extra principal, posting dates and any prepayment penalty. CFPB servicing guidance, last read September 30, 2026, explains that partial payments may be held until a full payment accumulates; it does not verify your rate or predict a particular biweekly plan. Escrow, taxes, insurance, HOA and fees are excluded. Use an actual payoff quote for closure.