Should I pay the mortgage or invest?
This tool compares mortgage payment schedules, not investment returns. The result alone does not decide how to use spare cash.
LEVEL 400 · REDUCE DRAG
Take Back the Timeline
Your mortgage payoff calculator. Compare your current payment with an extra-principal plan to see the time and interest you could reclaim.
READY WHEN YOU ARE—
Review the inputs, then select Calculate.
30-year rate with the same total interest
This is a hypothetical total-interest comparison, not APR or a refinance offer. Your actual note rate does not change.
Year-by-year payment schedules
Each row groups up to 12 monthly payments from the calculation month. The final payment is limited to the remaining balance plus that month’s interest.
Model assumptions and biweekly payments
The baseline keeps the regular payment unchanged. Your plan adds the entered extra principal every month, starting with the first modeled payment. Both start from the same current balance; past interest is excluded. No recast, adjustable rate, balloon, fees, tax effects or prepayment penalty is modeled.
Interest accrues at the annual note rate divided by 12, then payment is applied to interest and principal. The model retains full precision until display, treats balances of one cent or less as paid off, and stops at 100 years. Dates assume the first payment is one month after calculation, using UTC calendar months. Reopened plans retain their calculation-month anchor. These estimates are not a servicer payoff quote.
Twenty-six half-payments total one additional monthly payment per year. The shortcut spreads that amount across monthly payments. Actual biweekly results depend on the loan’s interest method and when the servicer credits payments; partial payments may be held until a full payment accumulates. Confirm principal-only handling, fees and any prepayment terms.
HOW TO USE THE RESULT
How extra mortgage payments change the loan
Extra principal reduces the balance that future interest is charged against. The impact depends on the remaining balance, interest rate, required principal-and-interest payment, and when the extra payment begins. Taxes, insurance, HOA dues, and mortgage insurance are not loan principal and do not accelerate payoff.
Does biweekly payment always help?
Twenty-six half-payments total thirteen monthly payments. This tool approximates that extra annual amount with monthly principal payments; actual biweekly timing depends on your loan and servicer. Twenty-four half-payments total only twelve monthly payments.
Will my servicer apply the extra correctly?
Confirm that additional money is marked principal-only and review the next statement. A faster payoff model is useless if the servicer treats the money as an early future payment.