Biweekly Mortgage Calculator
Paying your mortgage every two weeks instead of monthly results in 26 half-payments per year — equivalent to 13 full monthly payments instead of 12. That one extra payment per year cuts years off a 30-year mortgage and saves tens of thousands in interest.
Enter your loan amount, interest rate, and term to see exactly how many years you save by switching to biweekly payments, your total interest savings, and a year-by-year balance comparison.
| Year | Balance (Monthly) | Balance (Biweekly) | Difference |
|---|
Why Biweekly Payments Save So Much
The math behind biweekly mortgage payments is simple but powerful. A year has 52 weeks — divided by two gives 26 biweekly payment periods. Each payment is half your normal monthly amount. But 26 half-payments equals 13 full monthly payments per year. Compared to the standard 12 monthly payments, you're making one full extra payment per year — every year — applied entirely to principal.
That extra principal payment reduces the balance on which interest is calculated. Because mortgage interest is front-loaded (most of your early payments go to interest, not principal), reducing the balance early has a compounding effect: less interest accrues, so more of subsequent payments go to principal, which further accelerates payoff. On a $350,000 loan at 6.5%, this typically cuts 4–5 years off a 30-year mortgage and saves $60,000+ in interest.
Biweekly vs. Semi-Monthly — an Important Distinction
Many homeowners confuse "biweekly" with "twice a month" (semi-monthly). They are not the same. Biweekly = every 2 weeks = 26 payments/year. Semi-monthly = 24th and 15th = 24 payments/year. Only biweekly produces the extra 13th payment. Semi-monthly payments are mathematically identical to monthly — no benefit.
Do-It-Yourself: No Biweekly Program Needed
Many banks charge fees to enroll in formal biweekly payment programs. You can replicate the same result for free: divide your monthly payment by 12 and add that amount as extra principal each month. Or simply make one extra full monthly payment each December, designated as "extra principal." The math is identical — 13 payments per year — without any fees.
| Rate | Monthly Pmt | Biweekly Pmt | Years Saved | Interest Saved |
|---|---|---|---|---|
| 4.0% | $1,671 | $836 | ~4.2 yrs | ~$27,500 |
| 5.5% | $1,987 | $994 | ~4.5 yrs | ~$46,000 |
| 6.5% | $2,212 | $1,106 | ~4.7 yrs | ~$63,000 |
| 7.5% | $2,448 | $1,224 | ~5.0 yrs | ~$81,000 |
| 8.5% | $2,691 | $1,346 | ~5.3 yrs | ~$100,000 |
When Biweekly Payments Are Most Valuable
Biweekly payments make the most sense when you're early in your loan — the first 10 years are when interest costs are highest. If you're refinancing, consider starting biweekly from day one of the new loan rather than mid-term. For homeowners within 5–7 years of paying off their loan, the marginal benefit is smaller because the principal balance is already low.
For a full guide on the biweekly strategy including edge cases and alternatives, read Biweekly Mortgage Payments: How Much You Really Save. To understand how early payoff interacts with other mortgage costs like PMI, see What Is PMI and When Does It Go Away?
Related Reading
Also see: Mortgage Calculator for your standard payment breakdown, or Amortization Schedule for a full month-by-month payment table.
Frequently Asked Questions
How do biweekly mortgage payments work?
With biweekly payments, you pay half your normal monthly payment every two weeks. Since there are 26 biweekly periods in a year (not 24), you effectively make 13 full monthly payments per year instead of 12. That extra payment goes entirely to principal, reducing your balance faster and cutting years off your loan with no extra effort.
How many years does biweekly payment save?
On a standard 30-year mortgage, biweekly payments typically cut 4–6 years off the loan depending on the interest rate. At 6.5% on a $350,000 loan, switching to biweekly saves approximately 4–5 years and over $60,000 in interest. Higher interest rates produce larger savings because more of each payment goes to interest.
What is the difference between biweekly and semi-monthly payments?
Biweekly means every two weeks — 26 payments per year. Semi-monthly means twice a month — 24 payments per year. Only biweekly produces one extra full payment per year. Semi-monthly is mathematically identical to monthly payments — no savings benefit.
Do all lenders accept biweekly payments?
Most lenders accept biweekly payments, but some charge fees for formal biweekly programs. Confirm your lender applies each payment immediately to principal — not held until month-end. An alternative: add 1/12 of your monthly payment as extra principal each month, which replicates the same savings without any fees or special enrollment.
Is biweekly the same as making extra payments?
Yes — the math is equivalent. Making 26 biweekly half-payments equals 13 full monthly payments per year. You can replicate the same savings by adding 1/12 of your monthly payment as extra principal each month, or making one full extra monthly payment every December, without a formal biweekly program.