Half your payment every two weeks means 26 half-payments a year — 13 monthly payments instead of 12. Here is what that thirteenth payment is actually worth on your loan.
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Principal and interest only. Property taxes, homeowners insurance, PMI and HOA dues are not included.
You do not need a program, an enrollment or a fee. Adding one twelfth of your payment to each monthly payment produces virtually the same outcome, and you can stop any month you want.
A month is not four weeks. Twelve monthly payments cover the year, but a year holds 26 two-week periods, so half-payments every fortnight add up to 13 monthly payments. That thirteenth payment arrives with no interest attached to it — interest was already charged on the balance that month — so the entire amount lands on principal. From then on, every future month's interest is calculated on a smaller balance, and the effect compounds quietly for the rest of the loan.
The saving is larger the earlier in the loan you start and the higher your rate. On a 30-year mortgage taken out recently at 6–7%, going biweekly typically removes four to six years. On a loan with eight years left, it removes months, not years, because there is far less remaining interest to attack.
Companies still sell biweekly “programs” with a setup fee and a charge per transfer. They are selling you arithmetic you can do yourself. If your servicer offers a free biweekly option, use it; otherwise use the monthly equivalent above.
Some servicers hold the first half in suspense until the second arrives. You still get the thirteenth payment, but not the small bonus of paying early. It is worth one phone call to know which kind of servicer you have.
Biweekly works best if you are paid every two weeks, because two months a year contain three paychecks and those are the ones that fund the extra payment. If you are paid monthly, the monthly equivalent is simply easier to live with.
One structural point that trips people up: in the United States extra principal shortens the loan but never lowers the required monthly payment. If your goal is a smaller bill each month rather than an earlier finish, what you want is a recast, which the main calculator models alongside extra payments.
Yes, but through arithmetic rather than magic. A year has 52 weeks, so paying half your monthly payment every two weeks produces 26 half-payments, which is 13 full monthly payments instead of 12. That thirteenth payment goes entirely to principal, and on a typical 30-year loan it removes roughly four to six years and tens of thousands of dollars in interest.
Yes, and it is usually better. Add one twelfth of your payment to each monthly payment and designate it as principal. The saving is virtually identical, you keep control of the money, and you can stop any month you need to without renegotiating anything.
No. Third-party biweekly programs commonly charge a setup fee of several hundred dollars plus a per-transfer fee, for a service that adds nothing you cannot do yourself for free. If your servicer offers a genuine biweekly plan at no cost, that is fine; anything with a fee is not worth it.
Many do not. Plenty of servicers hold the first half in a suspense account until the second half arrives, then post one full payment. That still produces the thirteenth payment each year, so the benefit survives, but you lose the small extra saving from paying two weeks early. Ask your servicer how they post half-payments before assuming.
No. Like any extra principal payment in the United States, biweekly payments shorten the loan but never reduce the required payment. If a lower required payment is what you need, look at a recast instead, which re-amortizes the loan after a lump sum.
The main tool: extra payments, recast, payoff-vs-invest, biweekly, PMI removal and the full amortization schedule in one place.
Compare both terms side by side, including the third option most people miss: take the 30 and pay it like a 15.
How many months until a refinance pays for itself, and why a lower rate can still cost you more.
Biweekly payments are modeled as the mathematically equivalent extra twelfth of a payment applied to principal each month, which is what most servicers effectively produce. Every formula on this site is published in plain English on the methodology page, including a worked example you can verify by hand.
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These results are estimates, not financial advice. They depend entirely on the figures you enter and exclude taxes, insurance, PMI, HOA dues and any lender fee. Confirm your actual terms with your servicer and speak to a licensed professional before acting. Read the full disclaimer.