Mortgage Payoff and Amortization Calculator
Every payment splits between interest and principal. Watching that split shift is what makes extra payments worth making.
What This Calculator Does
Year by year, the calculator lays out interest paid, principal paid, and the balance still standing at each anniversary of your loan. Add an extra monthly amount or move to a biweekly rhythm and it recalculates the payoff date and the total interest against the original plan.
Who Is This For
Homeowners who want to see precisely where their money goes, owners aiming to be free of the mortgage before retirement, and anyone weighing whether spare cash belongs in the loan or somewhere else.
How It Works
Enter loan amount, rate, and term to build the base schedule. Layer on an extra monthly payment, or switch to the biweekly option, and compare payoff timelines and total interest against the original loan.
Frequently Asked Questions
Why is the early payment almost all interest?
Interest is charged against the outstanding balance, and that balance is never larger than on day one. Early payments therefore skew to interest and the split turns toward principal only by degrees. It is also why extra principal in the first years works far harder than the same dollars near the finish.
How does biweekly work?
Half the monthly amount goes out every two weeks. With 52 weeks in the year that produces 26 half payments — 13 monthly payments where 12 used to be. The thirteenth lands entirely on principal, shortening the term without much disruption to your budget.
Are extra payments really that effective?
They are, because each dollar of extra principal cancels all the future interest that dollar would have carried. The saving scales with the size of the extra payment and with how early it starts. Confirm with your servicer that the money is applied to principal rather than parked as a prepaid installment.
Should the mortgage be paid off early?
It turns on what else that money could do. Paying down a mortgage returns a guaranteed rate equal to your interest rate — persuasive when the rate is high, less so when it is low against the alternatives. Set it beside retirement contributions, an emergency reserve, and any higher-rate debt first.
Could there be a prepayment penalty?
Standard conforming mortgages generally have none, though some portfolio and investor loans do, often confined to the opening years. Read the note or ask your servicer outright before you begin making sizeable extra payments.