Bi-Weekly Mortgage Calculator
Switch your mortgage to bi-weekly payments and you make 26 half-payments a year — the equivalent of 13 monthly payments — which can shave years off the loan and tens of thousands off the interest. This free online financial calculator runs entirely in your browser — no signup, no data sent anywhere.
Inputs
Results
Interactive Chart
Drag to pan, scroll to zoom, shift+drag to box-zoom. Combined view of balance, principal paid, interest paid, and total paid.
Amortization Schedule
| Period | Payment | Principal | Interest | Balance |
|---|---|---|---|---|
| Click Calculate to generate the schedule. | ||||
How It Works (Formula & Method)
Mathematically, paying every two weeks is identical to paying an extra monthly_payment ÷ 12 each month. Because every extra dollar reduces the principal balance — and future interest is charged on that smaller balance — those small additions compound over the life of the loan. On a typical 30-year mortgage, the bi-weekly schedule pays off the loan in roughly 25–26 years and saves tens of thousands in interest.
Worked Example
Below is a worked example using the calculator's default values. The same numbers are pre-filled in the form above so you can press Calculate and see the result without typing anything.
Inputs used:
- Loan Amount ($): 300000
- Interest Rate (%): 6.5
- Loan Term (years): 30
With these inputs, the calculator computes the metrics shown in the Results panel. Change any value and press Calculate again to see how the result responds — the live widget and the chart both update instantly.
About the Bi-Weekly Mortgage Calculator
A bi-weekly mortgage payment plan splits your monthly mortgage payment in half and charges it every two weeks instead of once a month. Because there are 52 weeks in a year, that means 26 half-payments — the equivalent of 13 full monthly payments rather than 12. That single "extra" payment per year, applied directly to principal, dramatically accelerates payoff and reduces interest.
How to Use This Calculator
Enter the loan amount, interest rate, and term you would otherwise pay monthly. The calculator computes both the standard monthly payment and the equivalent bi-weekly payment, then shows the cumulative interest and time you would save by switching.
Tips & Considerations
- Set this up directly with your lender — do not just send half a payment yourself, since most lenders will hold the partial payment until the second half arrives.
- Check that there are no setup fees. Some lenders charge a fee for bi-weekly programs; you can replicate the savings for free by paying 1/12 extra each month.
- Bi-weekly works especially well if you are paid every two weeks at your job — your cash flow lines up naturally.
- Verify the extra is applied to principal, not held as a prepayment for the next month's interest.
Frequently Asked Questions
Is bi-weekly the same as twice-a-month?
No — twice a month is 24 payments per year, which exactly equals 12 monthly payments. Bi-weekly is every 14 days, giving you 26 half-payments (= 13 monthly equivalents) per year.
Will my lender automatically apply the extra to principal?
Usually yes when you sign up for their bi-weekly program. If you replicate it manually, note "apply to principal" on each extra payment.
Are there any downsides?
It is harder to skip a payment if you have a cash crunch, and some lenders charge setup fees. Make sure the lender does not lock you in.
How much can I really save?
On a $300k loan at 6.5% over 30 years, bi-weekly payments cut roughly 6 years off and save about $80,000 in interest.
Reviewed against: IRS publications, Consumer Financial Protection Bureau (consumerfinance.gov), and current published market data. Results are estimates for educational use only — not financial, tax, or legal advice.