Bi-Weekly Mortgage Payment Calculator
Calculate your bi-weekly mortgage payment and see how much interest you save compared to standard monthly payments by making 26 half-payments per year.
How to use this tool
- Enter loan amount, annual interest rate and loan term in the fields above.
- Results update instantly as you type — or click Calculate.
- Read your bi-weekly payment and the full breakdown beneath it.
⚠ This tool provides general estimates for education only and is not financial, tax or legal advice. Figures may not reflect your situation — verify with a qualified professional.
Formula
Monthly Payment: M = P × [r(1+r)n] / [(1+r)n − 1]
Bi-Weekly Payment: BW = M / 2
where P = principal, r = monthly interest rate (annual rate / 12), n = total months.
How it works
The bi-weekly mortgage strategy divides the standard monthly payment in half and pays that amount every two weeks. Since there are 26 bi-weekly periods per year (versus 12 months), the borrower effectively makes one extra monthly payment per year, accelerating principal reduction.
Interest savings are calculated by simulating bi-weekly amortization using the bi-weekly periodic rate (annual rate divided by 26) and comparing total interest paid against a standard monthly amortization schedule.
Worked example
$300,000 Loan at 6% for 30 Years
- Monthly rate r = 6% / 12 = 0.5% = 0.005. Term n = 360 months.
- Monthly payment M = 300,000 × [0.005 × (1.005)360] / [(1.005)360 − 1] = $1,798.65.
- Bi-weekly payment = $1,798.65 / 2 = $899.33.
- With 26 bi-weekly payments per year at the bi-weekly rate (6%/26 ≈ 0.2308%), the loan is paid off in roughly 24.5 years instead of 30.
Bi-weekly payment = $899.33; standard monthly payment = $1,798.65.
Common mistakes to avoid
- Assuming any biweekly payment plan is equivalent — some banks collect biweekly but only credit monthly, eliminating the interest-saving benefit.
- Forgetting that biweekly savings depend on making 26 half-payments per year (one extra full payment annually) — simply paying half the monthly amount twice a month (24 periods) has a different effect.
- Overlooking biweekly plan fees charged by some loan servicers, which can erode or eliminate the interest savings.
Key terms
- Bi-Weekly Payment
- A payment made every two weeks; 26 such payments per year equals one extra monthly payment annually.
- Amortization
- The process of gradually paying off a loan through regular payments that cover both interest and principal.
- Principal
- The outstanding loan balance on which interest is calculated.
- Periodic Interest Rate
- The annual interest rate divided by the number of payment periods per year (12 for monthly, 26 for bi-weekly).
- Interest Savings
- The reduction in total interest paid by adopting a bi-weekly schedule instead of a monthly one, resulting from faster principal paydown.
Frequently asked questions
- How does a biweekly schedule pay off a mortgage faster?
- 26 half-payments equal 13 full monthly payments per year instead of 12. That one extra payment per year reduces the principal faster, shortening the loan term and cutting total interest.
- Can I set up a biweekly payment myself instead of through my servicer?
- Yes. Simply make an extra principal-only payment once a year equal to one monthly payment. This achieves the same payoff acceleration without biweekly plan fees.
- Does biweekly payment reduce the interest rate?
- No. The interest rate on the loan is unchanged. Savings come purely from reducing the outstanding principal balance faster, on which daily or monthly interest is calculated.