Biweekly Mortgage Calculator
A biweekly mortgage schedule is one of the simplest ways to pay off a home loan years early and cut your total interest. Instead of one monthly payment, you pay half of that amount every two weeks. Because a year holds 52 weeks, that adds up to 26 half-payments, which is the same as 13 full monthly payments rather than the usual 12. The extra payment each year goes entirely to principal, so your balance shrinks faster and less interest accrues over the life of the loan. This calculator works out your standard monthly payment from the loan amount, interest rate and term, then simulates two complete repayment schedules side by side: a normal monthly plan and a biweekly plan that pays half the monthly amount every fortnight. It reports how long each plan takes to clear the loan and how much interest the biweekly approach saves. Enter your own loan to see the effect for your situation, because the savings grow with higher rates and larger balances. The Consumer Financial Protection Bureau recommends confirming how your servicer applies extra payments before you enroll in any program. Every figure here is computed deterministically, with a worked example below that reconciles exactly to the calculator.
Paying half the monthly amount every two weeks makes 26 payments a year, one extra month. On a $300,000 loan at 6.5%, biweekly payments of $948.10 save about $88,121.78 in interest.
Biweekly mortgage formula
M = P * r * (1 + r)^n / ((1 + r)^n - 1)
P = loan amount, r = annual rate / 100 / 12, n = years * 12
Biweekly payment = M / 2, paid every two weeks (26 per year)
Biweekly period rate = annual rate / 100 / 26
Each plan runs until the balance reaches zero
The standard monthly payment M is found with the amortization formula above. The biweekly plan pays half of M every fortnight at a per-period rate of the annual rate divided by 26. Across a year that is 26 half-payments, equal to 13 monthly payments, so one extra payment of principal is made each year and the loan clears sooner.
Worked example
A 300,000 loan at 6.5% over 30 years. The monthly payment is 1,896.20, so the biweekly payment is half of that, 948.10.
- Monthly rate = 6.5 / 100 / 12 = 0.00541667; n = 30 * 12 = 360
- Monthly payment M = 1,896.20
- Biweekly payment = 1,896.20 / 2 = 948.10, paid every two weeks
- Monthly plan: 360 payments, paid off in 30 years, total interest about 382,633.47
- Biweekly plan: 628 payments, paid off in about 24 years 2 months, total interest about 294,511.68
- Interest saved = 382,633.47 - 294,511.68 = 88,121.78
The biweekly plan clears the loan roughly 5.8 years early and saves about 88,121.78 in interest. These are the calculator's default inputs, so the results above match the widget.
Payments per year by schedule
The extra principal each year comes from paying 26 half-payments instead of 12 monthly payments.
| Schedule | Payments per year | Equals monthly payments | Extra per year |
|---|---|---|---|
| Monthly | 12 | 12 | 0 |
| Semi-monthly | 24 | 12 | 0 |
| Biweekly | 26 | 13 | 1 |
| Weekly | 52 | 13 | 1 |
Guidance on extra payments and servicer handling: US Consumer Financial Protection Bureau, Owning a Home.
Biweekly mortgage calculator: frequently asked questions
How does a biweekly mortgage pay off the loan faster?
You pay half of your monthly payment every two weeks. Because there are 52 weeks in a year, that means 26 half-payments, which equals 13 full monthly payments instead of 12. The one extra monthly payment each year goes straight to principal, so the balance falls faster and you reach zero years ahead of the standard schedule.
How much interest can a biweekly schedule save?
It depends on the loan amount, the rate and the term. On the default 300,000 loan at 6.5% over 30 years, the biweekly plan in this calculator pays the loan off in about 24 years and 2 months and saves roughly 88,000 in interest compared with the monthly schedule. A higher rate or a larger balance generally produces larger savings.
Is a biweekly mortgage the same as paying extra each month?
The effect is similar. A true biweekly plan adds the equivalent of one extra monthly payment per year. You can achieve almost the same result by dividing your monthly payment by 12 and adding that amount to each monthly payment, which avoids enrollment fees that some biweekly programs charge. The key driver is the extra principal, not the payment frequency itself.
Will my lender accept biweekly payments?
Not all servicers apply payments every two weeks, and some hold each half-payment until a full monthly amount arrives, which removes the benefit. The Consumer Financial Protection Bureau advises confirming how your servicer handles partial and extra payments before enrolling, and watching for setup or transaction fees. Making one extra full payment a year yourself is often simpler and free.
Are there downsides to a biweekly mortgage?
You commit to paying more each year, so the plan only helps if the budget is comfortable. Third-party biweekly services may charge fees that erode the savings. Some loans also carry prepayment penalties. Always check your loan terms and prefer paying extra principal directly to your servicer, at no cost, over a paid program.
Official sources
- Mortgage payments, extra payments and how servicers apply them: US Consumer Financial Protection Bureau, Owning a Home. As at 24 June 2026.
Reviewed by the CalculatorHub team, edited by James Graham, 24 June 2026. See our methodology. This is general information, not financial, tax, legal or investment advice.