Biweekly Mortgage Payment Calculator
Compare paying half your mortgage every two weeks against paying monthly, and see what the switch actually saves.
How this is calculated
Half the monthly payment made every two weeks is 26 half-payments a year, which equals 13 monthly payments rather than 12. The saving comes entirely from that extra payment.
A biweekly mortgage plan means paying half your monthly payment every two weeks instead of the full amount once a month. It is widely sold as a clever way to shave years off a mortgage, and it does work — but not for the reason most people assume.
The saving has almost nothing to do with paying more frequently. It comes from a quirk of the calendar. There are 52 weeks in a year, so 26 fortnightly payments. Twenty-six half-payments equal thirteen monthly payments, not twelve. You are simply making one extra monthly payment a year, and that extra payment goes entirely to principal.
The more frequent payment schedule does contribute a small additional saving, because your balance drops two weeks earlier each time and accrues slightly less interest. But that effect is minor. On a typical 30-year mortgage, the thirteenth payment accounts for the overwhelming majority of the benefit, and the extra frequency for a small remainder.
This matters because of what it implies. If the benefit is really just one extra payment a year, you can capture nearly all of it by dividing your monthly payment by twelve and adding that amount to each payment — no change to your schedule, no dependence on your lender supporting biweekly billing, and no third-party service.
That last point is the important one. Many lenders do not accept true biweekly payments and will simply hold the half-payment until the second half arrives, achieving nothing. Third-party biweekly conversion services exist to bridge that gap, and they typically charge a setup fee plus a per-transaction fee. Those fees can consume a meaningful share of the interest saved, which is a poor trade for a result you could have achieved for free.
Worked examples
A typical 30-year mortgage
$350,000 at 6.5% over 30 years, switching from monthly to biweekly.
Roughly five to six years come off the term. The extra you actually pay is one monthly payment a year — about $2,212 — and that alone drives nearly all of the saving.
Load this scenario into the calculatorA 15-year mortgage
The same balance and rate, but on a 15-year term.
The saving is much smaller in both years and dollars. Short terms are already principal-heavy, so there is far less future interest for the extra payment to cancel.
Load this scenario into the calculatorA high-rate loan
$250,000 at 9% over 30 years.
The higher the rate, the more each extra dollar of principal is worth. Biweekly conversion is most valuable exactly when borrowing is most expensive.
Load this scenario into the calculatorWhat this assumes
- Your lender applies each biweekly payment immediately rather than holding it until a full monthly payment has accumulated. Many do not.
- No setup or per-payment fee is charged. Third-party biweekly services usually charge both.
- The rate is fixed and payments continue uninterrupted for the whole term.
- Interest on the biweekly schedule is accrued per fortnight at the annual rate divided by 26, which is the standard convention but may differ slightly from your lender's day-count method.
- Principal and interest only — escrow items are excluded.
Common questions
- Does paying biweekly really cut years off a mortgage?
- Yes, but because it makes you pay 13 monthly payments a year instead of 12, not because of the frequency. Twenty-six half-payments is thirteen whole ones. Almost the entire benefit is that thirteenth payment going to principal.
- Is a biweekly plan better than just paying extra each month?
- Barely. Dividing your monthly payment by twelve and adding it each month captures nearly the same saving, keeps you in control, and costs nothing. The biweekly schedule adds a small extra benefit from paying two weeks earlier each cycle, which is real but minor.
- Should I pay a company to set up biweekly payments?
- Generally no. These services typically charge a setup fee and a per-transaction fee to do something you can do yourself by adding to your monthly payment. Run the numbers: if the fees exceed a small fraction of the interest saved, you are paying for convenience rather than savings.
- Will my lender accept biweekly payments?
- Many will not apply them as you intend. Some hold the first half-payment until the second arrives, then post it as a normal monthly payment — which produces no saving at all. Ask specifically whether payments are applied on receipt before assuming the schedule works.
- Does this affect my credit score?
- Not directly. Credit scoring cares whether payments are made on time and how much you owe. Paying down the balance faster helps over time by reducing your debt, but the payment frequency itself is not a scoring factor.
Related calculators
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- Amortization Schedule Calculator — See the full month-by-month breakdown of any loan — what you pay, what goes to interest, and what you still owe.
- Credit Card Payoff Calculator — See how long your card takes to clear on minimum payments versus a fixed amount, and what the difference costs you.