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Biweekly Mortgage Payment Calculator

Pay half your mortgage every two weeks instead of the full amount monthly, and watch how much interest disappears — plus the years you shave off the loan.

Biweekly mortgage payments

Enter your mortgage and see the before-and-after of a biweekly schedule — every two weeks you pay half the monthly amount.

How it works: the standard monthly payment comes from the amortization formula; then the calculator simulates both plans period by period — 12 monthly payments a year versus 26 half-payments — crediting each biweekly half to principal and interest on the day it lands. That is why the 26 half-payments (worth 13 full monthly payments) bite hardest in the early years, when the balance is biggest.

How biweekly mortgage payments work

A monthly schedule has 12 payments a year. A biweekly schedule has 26 half-payments a year — which adds up to 13 full monthly payments. That one extra full payment a year lands entirely on the principal, and because the balance is smaller from then on, every following month accrues a little less interest. The effect compounds: on a typical 30-year loan, biweekly payments can remove roughly 6 years and save six figures of interest.

The formula

monthly payment = balance × r ÷ (1 − (1 + r)^−months) where r = APR ÷ 12 ÷ 100 · then: biweekly payment = monthly ÷ 2, credited every 2 weeks at APR ÷ 26 ÷ 100

There is no closed-form shortcut for the savings, because each biweekly payment changes the balance for every period after it. The calculator replays the loan twice — once monthly, once biweekly — and compares the total interest and payoff points.

Worked example

A $300,000 mortgage at 7% APR with 30 years left has a standard payment of $1,995.91 a month. Switch to biweekly: $997.95 every two weeks. The loan is paid off in 23 years and 9 months — 75 months early — and total interest falls from $418,526.69 to $315,138.77. You keep $103,387.92.

Where this comes in handy

New home buyers: see how much a biweekly plan really matters before you sign up for the lender's program.
Refinancing: compare a lower-rate 30-year loan plus biweekly payments against a plain 15-year loan.
Budget check: two months a year will have three biweekly payments instead of two — confirm your cash flow handles those months.
Program fees: weigh a lender's biweekly-plan fee against doing the same thing yourself for free with an extra principal payment each month.

Biweekly mortgage payments — frequently asked questions

Why do 26 half-payments beat 12 full payments so much?

Because 26 halves equal 13 full payments. That thirteenth monthly payment, landing on the principal each year, shrinks the balance early — and interest is charged on the remaining balance, so every later month costs less. The savings concentrate in the loan's early years, when the balance is largest.

Is biweekly the same as adding 1/12 extra to my monthly payment?

Nearly. Adding one-twelfth extra to each monthly payment also creates 13 full payments a year, so the savings are very close — biweekly wins by a hair because each half lands a bit earlier, earning slightly more interest reduction. If your lender doesn't offer biweekly, the monthly add-on gets you almost the same result.

Will biweekly payments lower my required monthly payment?

No. Extra money shortens the loan — the scheduled payment amount stays the same until the loan is gone. Your payment only drops if you refinance or your lender recasts the loan. The calculator shows this by moving the payoff date, not the payment.

Should I pay my lender's biweekly plan fee, or do it myself?

Do the math first: fees eat directly into your savings. Many lenders will simply accept an extra principal payment with your regular monthly payment — free — and you can set it to one-twelfth of your payment to mirror the 13th-payment effect. Third-party "biweekly" services that debit you then pay the lender monthly are often the worst deal: you pay fees for a schedule that isn't even truly biweekly.

Do biweekly payments affect taxes or escrow?

The calculator and the math cover principal and interest only. Your property taxes and insurance are still owed in full, either way, and the biweekly half-payments go to principal and interest first — escrow gets no extra. Keep paying taxes and insurance on their normal schedule.

Which months have three biweekly payments?

Two months each year contain three biweekly paydays instead of two (which months depends on your pay calendar). Those months are the "extra payment" that makes the plan work, so budget for them — the other ten months feel like an ordinary half payment twice.

Does every lender offer a biweekly option?

No — some servicers only accept full monthly payments, and some credit partial payments only when they add up to a full one. If your lender won't do true biweekly, the free workaround is a single extra principal payment of one-twelfth your payment each month. Ask your servicer exactly how extra money is credited before you commit.

What if my servicer holds my half-payments until they make a full one?

Then you save almost nothing. Some servicers park a lone half-payment in a "suspense" or unapplied-funds account until the second half arrives — the balance never shrinks early, so interest accrues exactly as if you were paying monthly. This is the single most important thing to confirm in writing: your halves must be applied to principal and interest the day they land, not warehoused.

How does this compare with just paying extra each month?

It's the same family of strategy. The extra loan payment calculator handles arbitrary extra amounts on any loan, while this page models the classic 26-half-payment biweekly schedule on a mortgage. For picking which mortgage to put the money on, the mortgage affordability calculator sets the right budget first.