Biweekly vs Monthly Payoff Calculator
See how paying half your mortgage every two weeks slips in one extra payment a year — shortening the loan and cutting interest.
How it works
26 biweekly half-payments = 13 monthly payments per year (one extra) · Monthly payment = P·r ÷ (1 − (1+r)^−n) · Biweekly plan amortizes at 13/12 of that payment
A biweekly plan splits your monthly payment in half and collects it every two weeks. Because a year has 26 fortnights, you make 26 half-payments — the equivalent of 13 full monthly payments, one more than the standard 12. That single extra payment each year goes entirely to principal, quietly shaving years and thousands of dollars off the loan.
Worked example
On a $300,000 loan at 6.5% over 30 years, the monthly payment is about $1,896. Paying $948 every two weeks adds one extra payment a year, paying the loan off roughly 4–5 years early and saving well over $60,000 in interest.
Frequently asked questions
How does biweekly save so much?
It sneaks in a 13th monthly payment each year, all of which reduces principal. Less principal means less interest for the entire remaining life of the loan, and the savings compound.
Do I need a special biweekly program?
No — and many charge setup fees. You can get the same result yourself by paying 1/12 of a payment extra each month, or making one extra full payment a year toward principal.
Will my lender apply biweekly payments correctly?
Some servicers hold the half-payment until the second one arrives rather than applying it early. Confirm how yours handles it, or simply add extra principal to your normal monthly payment.
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Educational estimate, not financial advice. Confirm figures with your lender or a licensed professional.