Crunch My Mortgage

Biweekly mortgage payment calculator

Compare paying half your mortgage payment every two weeks with paying monthly: how much sooner the loan ends, the interest saved, and a simpler way to get nearly the same result.

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Your loan

Your current balance, or the amount of a new loan.

The note rate on your loan, not the APR.

Results

Interest saved by paying biweekly $74,440

Paid off in 24 years 6 months, 5 years 6 months sooner than paying monthly

Monthly $347,515 total interest $1,798.65 a month Paid off in 30 years
Biweekly $273,075 total interest $899.33 every two weeks Paid off in 24 years 6 months

Twenty-six half-payments a year add up to 13 monthly payments, so you pay $1,798.78 more each year. Adding one-twelfth of a payment, $149.89, to every monthly payment sends about the same extra; its result is shown below.

Half payment, every two weeks
$899.33
Extra paid per year
$1,798.78
Monthly + 1/12: paid off in
24 years 7 months
Monthly + 1/12: interest saved
$73,667

Balance: biweekly vs monthly

Balance at the end of each year under each schedule. Hover or tap the chart for any year.

  • Biweekly
  • Monthly

A biweekly year here is 26 payments (364 days), so it runs about a day ahead of the calendar each year.

What this calculator does

It shows what happens if, instead of one full payment a month, you pay half of it every two weeks: how much earlier the mortgage is paid off and how much interest you avoid.

A year has 52 weeks, so paying every two weeks means 26 half-payments, which add up to 13 full monthly payments instead of 12. That one additional payment a year goes entirely to principal, and it is the main reason a biweekly schedule finishes early. In most years, two months get three payments instead of two.

Enter your balance, rate and the years left. The results compare the two schedules side by side: payment per period, payoff time and total interest. They also show a third approach, adding one-twelfth of the monthly payment to every monthly payment, which sends about the same extra money each year without changing when you pay.

How the math works

The calculator models a true biweekly loan: every two weeks you pay half the monthly payment, and interest for that period is the balance times 1/26 of the annual rate. Because the balance is reduced every two weeks, each period's interest is figured on a slightly smaller balance than a monthly loan would carry.

Over a year you pay 26 × (M ÷ 2) = 13 × M, one monthly payment more than the usual 12 × M. With a fixed half-payment, the number of biweekly periods needed is:

n = −ln(1 − rB ÷ H)ln(1 + r)
n
number of biweekly payments until the balance is zero (round up); years = n ÷ 26
B
current balance
r
rate per period: the annual rate ÷ 26 (6.5% → 0.0025)
H
half of the regular monthly payment

The calculator runs the full schedule period by period with interest rounded to the cent, and converts the result to years and months at 26 periods a year. The monthly comparison is a standard amortization schedule.

Not every biweekly program works this way. Some servicers collect your half-payments, hold them, and apply a full payment once a month, so interest is still charged monthly and the extra money reaches the loan as one additional payment a year. That arrangement lands close to the 1/12 method shown in the results.

Worked example

Take a $250,000 loan at 6.5% with 30 years left.

Worked example

  1. The monthly payment is $1,580.17, so the biweekly payment is half of that: $790.09.
  2. In a year that is 26 × $790.09 = $20,542.34, compared with 12 × $1,580.17 = $18,962.04: $1,580.30 more, about one monthly payment.
  3. The rate per period is 6.5% ÷ 26 = 0.25%. The first period's interest is $250,000 × 0.25% = $625.00, so $165.09 of the half-payment reduces the balance.
  4. With the formula: −ln(1 − 0.0025 × $250,000 ÷ $790.09) ÷ ln(1 + 0.0025) = 627.04, so 628 biweekly payments, or about 24.2 years.

Paying biweekly ends the loan in 24 years 2 months instead of 30 years and cuts total interest from $318,862 to $245,422, a saving of $73,439.

The 1/12 method gets very close. Adding $131.68 to each monthly payment pays the loan off in 24 years 2 months and saves $72,714. The small gap comes from timing: under true biweekly, part of the extra reaches the balance a little earlier.

Common mistakes

  1. Assuming every biweekly plan is true biweekly. Many programs hold your half-payments and apply them monthly. Ask your servicer exactly when each payment is credited, because that decides which result above applies to you.
  2. Paying fees for something you can do yourself. Some third-party payment programs charge enrollment or per-payment fees. Adding one-twelfth of a payment to each monthly payment produces nearly the same savings at no cost, so weigh any fee against the difference.
  3. Sending half-payments without an arrangement. If the servicer is not set up for biweekly payments, a half-payment may be held as unapplied funds, and the full monthly payment is still due on its due date. A missed or partial payment may be treated as late.
  4. Confusing biweekly with twice a month. Paying on the 1st and 15th is 24 half-payments, exactly 12 monthly payments. The saving comes from the extra money, not from paying more often.
  5. Forgetting the three-payment months. In most years, two months each get a third biweekly payment, which matters if you budget month by month.

Limits of this estimate

  • It models true biweekly payments with interest at 1/26 of the annual rate each period. A program that applies payments monthly will look more like the 1/12 result.
  • A biweekly year here is 26 payments, or 364 days, and payoff time is converted at 26 payments a year, so calendar dates can drift by a day or two each year.
  • It covers principal and interest only, at a fixed rate. Escrow for tax and insurance is not included.
  • Program fees are not included. Subtract any you would pay from the interest saved.
  • Loans that charge interest daily, or servicers that credit payments a few days after receipt, can produce slightly different figures.

Frequently asked questions

How much does paying biweekly save?

It depends on the balance, the rate and how many years are left; the savings come mostly from the one extra payment a year. In the example on this page, a $250,000 loan at 6.5% over 30 years, true biweekly payments save $73,439 and end the loan 5 years 10 months early. Enter your own numbers above for your loan.

Is biweekly the same as paying twice a month?

No. Twice a month is 24 half-payments a year, which adds up to exactly 12 monthly payments, so there is no extra payment and very little saving. Every two weeks is 26 half-payments a year, because a year has 52 weeks. Those two additional half-payments are what shorten the loan.

Can I set up biweekly payments myself?

Ask your servicer whether it accepts biweekly payments and, if so, when each half-payment is credited to the loan. If it only accepts monthly payments, you can reach nearly the same result by adding one-twelfth of a payment to each monthly payment, marked as principal, or by making one extra payment a year.

Why does the calculator also show a 1/12 method?

Because it is how many people get the biweekly effect without changing their payment schedule, and because a program that collects half-payments but applies them once a month behaves much like it. Comparing the two lines shows how close they are for your loan.

Does this work on a loan I already have?

Yes. Enter the current balance from your statement and the years left on the loan. The calculator compares the remaining monthly schedule with switching to biweekly from today.

Will biweekly payments help me drop PMI sooner?

They can, because the extra principal brings the balance down faster. On most conventional loans you can ask to cancel PMI once the balance reaches 80% of the home's original value. The PMI removal calculator shows that date with extra payments.

Next steps: to try the 1/12 approach, or any other extra amount, open the extra payment calculator with your numbers filled in. If you have a lump sum instead, the recast calculator compares lowering the payment with shortening the loan. For the full monthly cost with tax and insurance, see the mortgage payment calculator.