Biweekly Payment Calculator
One extra payment a year, on autopilot — see the interest saved and years shaved off with biweekly payments.
Biweekly = half your monthly payment every 14 days. That's 26 half-payments a year — the equivalent of one extra full payment annually.
- Monthly payment$2,212.24 × 12/yr
- Biweekly payment$1,106.12 × 26/yr
- Monthly payoff time30 yrs
- Biweekly payoff time24 yrs 2 mo
- Interest saved$102,808.74
The magic is just arithmetic: 26 half-payments = 13 full monthly payments per year. That one extra payment goes entirely to principal, which compounds into 6.50% interest savings year after year. Before switching, confirm your lender applies partial payments to principal without a prepayment penalty.
How the math works
A biweekly schedule takes your standard monthly mortgage payment, cuts it in half, and has you pay that half every two weeks instead of once a month. Because a year has 52 weeks, you make 26 half-payments — the equivalent of 13 full monthly payments instead of 12. That one extra full payment each year goes entirely to principal, and that is where the savings come from.
Mortgage interest accrues on the outstanding balance, so every extra dollar of principal shrinks the balance that future interest is charged on. Timing amplifies the effect: a standard amortization schedule is front-loaded with interest, meaning most of your early payments cover interest while only a sliver reduces principal. Extra principal paid early eliminates the most future interest, which is why a single extra payment per year can shave several years off a 30-year loan.
The formula is straightforward: biweekly payment = standard monthly payment ÷ 2, paid 26 times per year at a per-period rate of annual rate ÷ 26. The result is mathematically identical to making one extra monthly payment per year — biweekly simply automates it, and it lines up neatly if you are paid every two weeks. One caution: some servicers park half-payments in a holding account until they add up to a full payment, which delays the principal reduction. Confirm your lender credits each half-payment to principal immediately.
Worked example
Take a $300,000 mortgage at 6.5% APR on a 30-year term. The standard monthly payment is $1,896.20, and staying on schedule means paying about $382,633 in total interest. Switch to biweekly — $948.10 every two weeks — and the loan pays off in about 24.1 years instead of 30, a full 5.9 years early. Total interest drops to roughly $294,512, saving about $88,100, while your budget barely notices because each payment is half of what you were already paying. The only real change: twice a year a month contains a third biweekly payment, quietly adding up to one extra monthly payment per year.
What to watch for
- Confirm how your servicer applies half-payments. Some hold partial payments in a suspense account until they total a full payment, delaying principal reduction. Ask for each half-payment to be credited to principal right away.
- Check for enrollment fees or prepayment penalties before signing up. A modest one-time fee can still be worth it on a large mortgage, but federal rules bar prepayment penalties on most residential mortgages — verify with your servicer.
- You can replicate the effect yourself: add 1/12 of your monthly payment as extra principal each month, or make one extra full payment per year. The math is identical, with no program needed.
- Biweekly fits naturally if you are paid every two weeks, since payments line up with paychecks. If you are paid monthly, the add-extra-principal approach is simpler to manage.
- Compare against refinancing first. If rates have fallen since you borrowed, refinancing to a lower rate may save more than biweekly payments — and you can combine both strategies.
Frequently asked questions
How do biweekly mortgage payments work?
Instead of one monthly payment, you pay half the amount every two weeks. That's 26 half-payments a year — the equivalent of 13 full monthly payments instead of 12. The extra payment goes entirely to principal.
How much can biweekly payments save?
On a typical 30-year mortgage, biweekly payments often cut 4–6 years off the loan and save tens of thousands in interest — without increasing what you pay each month in any meaningful way.
Is there a downside to biweekly payments?
Two things to check: some lenders charge a fee to set up biweekly billing, and some apply partial payments to a holding account rather than principal immediately. Confirm your lender credits half-payments to principal with no prepayment penalty.
Can I get the same effect without biweekly billing?
Yes — just add 1/12 of your monthly payment as extra principal each month, or make one extra full payment per year. The math is identical; biweekly just automates it.
Does a biweekly schedule work for car loans too?
Yes — the same math applies to any amortizing loan with no prepayment penalty. On a 60-month auto loan, biweekly payments can cut several months off the term and save hundreds in interest, because each extra half-payment attacks principal directly.
What happens in months with three biweekly payments?
Twice a year a month contains three biweekly pay dates instead of two. That is not an error — those two extra half-payments per year are exactly what adds up to the 13th monthly payment. Budget for them as part of the plan rather than treating them as a surprise.
Can my lender charge a prepayment penalty for biweekly payments?
On most U.S. residential mortgages, federal rules prohibit prepayment penalties, and FHA, VA, and USDA loans never carry them. Some servicers charge a one-time setup fee for their biweekly billing program instead — a fee, not a penalty. Read your loan documents or ask your servicer directly.
Is biweekly better than refinancing to a 15-year loan?
A 15-year refinance usually brings a lower rate and a forced faster payoff, but the required payment is much higher and closing costs run into the thousands. Biweekly costs nothing extra and keeps your required payment at the 30-year level, preserving flexibility if money gets tight.