Biweekly Mortgage Calculator

Compare standard monthly vs biweekly mortgage payments, see interest savings, and find your new payoff date. Supports extra payments and a full amortization schedule.

Biweekly mortgage payment calculator

$

Use your current remaining balance if you already have a mortgage.

%
years
months

Total original term (e.g., 30 years).

years
months

If you already made payments, we adjust the remaining term.

Used to estimate payoff dates. Leave blank to use today.

$

Extra per monthly payment.

$

Extra per biweekly payment.

Biweekly plan Monthly plan

Monthly vs biweekly comparison

Monthly plan

Standard 12 payments per year

Monthly payment
$0
Total interest
$0
Payoff date
–

Biweekly plan

26 half-payments per year

Biweekly payment
$0
Total interest
$0
Payoff date
–

Savings with biweekly

Compared with standard monthly payments

Interest saved
$0
Time saved
–
Extra paid per year
$0

Amortization schedule

Scroll to see how each payment is split between principal and interest, and how quickly your balance falls under each plan.

# Date Payment Principal Interest Balance
Enter your details and click Calculate to see the schedule.

How this biweekly mortgage calculator works

This tool compares a standard monthly mortgage with a biweekly payment plan using the same loan balance, interest rate, and term. It shows:

  • Your required monthly payment and payoff date.
  • The equivalent biweekly payment, payoff date, and total interest.
  • How much interest and time you save by switching to biweekly payments.

Formulas used

1. Monthly payment

For a fixed-rate mortgage:

Monthly rate: \( r_m = \dfrac{r_{annual}}{12} \)

Number of months: \( n = \text{years} \times 12 \)

Monthly payment:

\[ P_{month} = \dfrac{L \cdot r_m}{1 - (1 + r_m)^{-n}} \]

where \( L \) is the loan balance.

2. Biweekly payment

We approximate biweekly payments by:

  • Biweekly rate: \( r_{bw} = \dfrac{r_{annual}}{26} \)
  • Number of periods: \( n_{bw} = \text{years} \times 26 \)

\[ P_{bw} = \dfrac{L \cdot r_{bw}}{1 - (1 + r_{bw})^{-n_{bw}}} \]

This is slightly more precise than simply taking half the monthly payment, because interest is compounded more frequently.

Why biweekly payments save interest

There are 26 biweekly periods in a year. Paying half your monthly payment every two weeks means you make the equivalent of 13 full monthly payments per year instead of 12. That extra payment goes directly toward principal, which:

  • Reduces your balance faster.
  • Reduces the interest charged each period.
  • Shortens your payoff time by several years on a typical 30-year loan.

Biweekly vs extra monthly payments

Mathematically, biweekly payments and making one extra full payment per year are very similar if the total extra principal is the same. The main differences are:

  • Timing: Biweekly payments chip away at principal throughout the year, slightly increasing savings.
  • Behavior: Biweekly plans align with many people’s paychecks and automate the extra payment.
  • Flexibility: Extra monthly payments are easier to pause or adjust if your cash flow changes.

Use the “Extra principal payments” fields to model both strategies and see which works best for you.

Practical tips before switching to biweekly payments

  • Ask your lender how they apply payments. Some “biweekly” programs simply hold your extra payment and apply it once per month, which reduces the benefit.
  • Watch for fees. If your lender charges setup or processing fees, you may be better off self-managing extra principal payments.
  • Confirm there are no prepayment penalties. Most modern mortgages don’t have them, but always check.
  • Automate if possible. Whether you choose biweekly or monthly with extra principal, automation helps you stay consistent.

Biweekly mortgage FAQs

Is a biweekly mortgage always a good idea?

It’s usually a good idea if:

  • You plan to stay in the home long enough to benefit from the interest savings.
  • You have a stable income and can comfortably afford the higher annual outlay (13 payments instead of 12).
  • Your lender doesn’t charge high fees or restrict extra principal payments.

If you have high-interest debt (like credit cards), it may be smarter to pay that down first.

Can I create my own biweekly plan without my lender?

Yes. Two common DIY approaches are:

  • Make half your monthly payment every two weeks and ensure at least the full monthly amount is received before the due date.
  • Add 1/12 of your monthly payment as extra principal each month (equivalent to one extra payment per year).

Always label extra amounts as “principal only” in your online banking or payment memo.

What if I miss a biweekly payment?

As long as you still make at least the required monthly payment by the due date, you won’t be reported late. You’ll simply lose some of the interest savings for that period. If you’re using a lender-managed biweekly program, ask how skipped payments are handled.

Does this calculator work for existing mortgages?

Yes. Enter your current balance and either:

  • Use the “Time already paid” fields to approximate your remaining term, or
  • Directly enter your best estimate of the remaining years and months.

The results will then show how switching to biweekly payments from now on would affect your payoff date and total interest.