Bi-Weekly Mortgage Payment Calculator
See how much time and interest you save by switching from monthly to bi-weekly mortgage payments. Ideal for homeowners who want to pay off their loan faster without a dramatic budget change.
About this calculator
A standard monthly mortgage uses 12 payments per year. Switching to bi-weekly payments means 26 half-payments annually — the equivalent of 13 full monthly payments. That extra payment each year chips away at your principal faster, reducing the outstanding balance on which interest accrues. The monthly payment is calculated with the standard amortization formula: M = P × r(1+r)ⁿ / ((1+r)ⁿ − 1), where P is the loan amount, r is the monthly interest rate, and n is the number of months. The bi-weekly payment is simply M / 2, plus any optional extra principal. The calculator then simulates both payment schedules month by month to find how many fewer periods you need, expressing the difference in years saved.
How to use
Suppose you have a $300,000 mortgage at 6.5% interest over 30 years. The standard monthly payment is approximately $1,896. Switching to bi-weekly, you pay $948 every two weeks (26 times per year). The simulator runs both amortization schedules: the monthly schedule takes 360 periods while the bi-weekly schedule finishes in roughly 310 bi-weekly periods — about 4.5 years sooner. Total interest saved is approximately $58,000. Add an extra $100 per payment to shorten the loan even further.
Frequently asked questions
How much interest can I save by switching to bi-weekly mortgage payments?
On a typical $300,000 30-year mortgage at 6.5%, switching to bi-weekly payments saves roughly $50,000–$60,000 in total interest. The savings come from making one extra full payment per year, which continuously reduces your principal balance faster. The higher your interest rate or loan balance, the greater the savings will be.
What is the difference between a bi-weekly mortgage payment and a semi-monthly payment?
Bi-weekly means you pay every two weeks, resulting in 26 payments per year — the equivalent of 13 monthly payments. Semi-monthly means you pay twice a month on fixed dates, totalling exactly 24 payments per year, which equals 12 monthly payments. Only the bi-weekly schedule delivers the bonus 13th payment that accelerates payoff.
Can I make bi-weekly mortgage payments with any lender?
Many lenders allow bi-weekly payments, but some require you to enrol in a formal program or charge a setup fee. Always verify with your lender that extra payments are applied directly to principal, not held until month-end. If your lender doesn't offer bi-weekly billing, you can replicate the effect by adding 1/12 of your monthly payment as extra principal each month.