MortgageComparisonTools

Biweekly Mortgage Calculator

See what switching to fortnightly payments actually does: one extra monthly payment a year, and the time it removes.

Last reviewed

·

Free · No sign-up · Runs in your browser

Biweekly mortgage plans are marketed as a clever structural saving. They are not: twenty-six half payments a year equals thirteen monthly payments, and the thirteenth payment is the entire effect.

This calculator shows exactly that - the extra amount paid each year, the interest it saves, and the months it removes - so the plan can be compared against simply paying the same extra amount voluntarily.

Your numbers

Results update as you type. Nothing is sent anywhere.

Result

Interest saved

$78,576

Time removed

5.4 years

Monthly payment
$1,919
Biweekly payment
$959
Paid per year - monthly
$23,023
Paid per year - biweekly
$24,941
Extra paid per year
$1,919
Months removed
65 months
New payoff time
295 months

Twenty-six half payments a year add up to thirteen monthly payments, and that thirteenth payment is what shortens the loan.

Some servicers hold each half payment until a full payment is available, which removes the benefit. Ask how yours applies bi-weekly funds before signing up.

How to use the biweekly mortgage calculator

  1. Enter the loan amount, rate and term.
  2. Read the biweekly payment - it is exactly half the monthly one.
  3. Compare what is paid per year under each schedule.
  4. Compare the interest saved against setting up the same extra payment yourself.

What people use this for

  • Deciding whether a biweekly plan is worth setting up.
  • Comparing a paid biweekly service against doing it yourself.
  • Understanding the mechanism behind the marketing.
  • Estimating the effect of one extra payment a year.

Worked examples

Every figure below is produced by running this calculator against the example inputs, so the numbers always match the tool.

A 30-year loan

$320,000 at 6% over 30 years switched to fortnightly payments.

Interest saved
$78,576
Time removed
5.4 years
Extra paid per year
$1,919

A 15-year loan

The same amount at 5.4% over 15 years, where there is less interest to save.

Interest saved
$18,305
Months removed
20 months
New payoff time
160 months

The mechanism is one extra payment

There are fifty-two weeks in a year, so twenty-six fortnightly half payments total thirteen monthly payments rather than twelve. That thirteenth payment goes entirely to principal, and it is the whole of the benefit.

The same result comes from dividing one monthly payment by twelve and adding it to each month, or from making one extra payment a year whenever it suits. No service or arrangement is required to do it.

Watch how the servicer applies the money

Some servicers hold each half payment until a full payment is available, then apply it on the normal date. That produces exactly the same result as paying monthly, and none of the benefit.

Some third-party biweekly services charge a setup fee and a per-transaction fee for something you can arrange free with the servicer. Ask how funds are applied and what it costs before signing up.

Methodology and assumptions

What this calculator does, and what it deliberately does not do.

  • The biweekly payment is half the monthly payment. Twenty-six of them per year equal thirteen monthly payments.
  • The comparison applies the surplus as an extra monthly amount and re-amortises to find the shortened payoff.
  • The result assumes the servicer applies extra funds to principal on receipt.
  • Results are estimates. Real quotes depend on credit, income, property, loan programme and lender pricing at the time of application.
  • Nothing you type is transmitted or stored - the calculation runs entirely inside your browser.

This calculator is provided for informational and educational purposes only. Results are estimates and may not reflect actual rates, fees, taxes, or market conditions.

This website is not a lender, a mortgage broker or a financial adviser. It does not originate loans, does not accept applications and does not forward your details to anyone.

Actual loan terms depend on credit history, income, the property, the loan programme and lender pricing at the time of application. Only a lender can tell you what you qualify for.

Frequently asked questions

Is a biweekly plan better than paying extra monthly?

They are the same thing arithmetically. Paying extra monthly is more flexible and usually free.

Should I pay for a biweekly service?

Rarely. It provides no benefit you cannot arrange directly with your servicer, and the fees erode the saving.

Does the lender have to accept extra payments?

Most mortgages allow prepayment without penalty, but some carry prepayment terms. Check the note before assuming.

Will my payment stay the same?

On a fixed-rate loan yes - extra payments shorten the term rather than reducing the payment, unless you specifically request a recast.

Related calculators

More loan comparison tools on MortgageComparisonTools.

Browse all 4 tools →