Mortgage Payoff and Amortization Calculator
Follow the split between interest and principal across every year of the loan — and see what a modest extra payment rearranges.
What This Calculator Does
A full year-by-year schedule comes out of this calculator: interest paid, principal paid, and the balance still standing at each year's close. Introduce an extra monthly amount or switch to a biweekly rhythm and it recalculates the payoff date and total interest beside the original plan.
Who Is This For
Created for homeowners who want to see precisely where their payments land, owners aiming to be mortgage-free before retirement, and anyone deciding whether spare cash belongs in the loan or somewhere else entirely.
How It Works
Supply your loan amount, interest rate, and term to build the base schedule. Then add an extra monthly payment or select the biweekly option, and the calculator compares payoff timelines and total interest against the original loan.
Frequently Asked Questions
Why does interest dominate my early payments?
Interest accrues on the outstanding balance, and that balance is at its largest on day one. Early payments therefore lean heavily toward interest, with the split turning gradually toward principal over time. It is also why extra principal applied in the first years accomplishes far more than the same amount applied near the end.
How does the biweekly method work?
You pay half your monthly amount every two weeks. Since a year holds 52 weeks, that yields 26 half payments — the equivalent of 13 monthly payments rather than 12. The additional payment goes straight to principal, shortening the term without much disruption to your budget.
Are extra payments genuinely worth it?
They can be, because each dollar of extra principal erases all the future interest that dollar would have accrued. The benefit grows with the size of the extra payment and with how early you begin. Confirm with your servicer that extra funds are applied to principal instead of being held as a prepaid future installment.
Should I clear the mortgage early?
That depends on what else the money could accomplish. Paying down a mortgage returns a guaranteed amount equal to your interest rate, which is compelling when the rate is high and less so when it is low relative to other options. Weigh it against retirement contributions, an emergency reserve, and higher-rate debt first.
Could there be a prepayment penalty?
Most standard conforming mortgages carry none, though some portfolio and investor loans do, frequently only within the first few years. Read your note or ask your servicer directly before you begin making sizeable extra payments.