Biweekly mortgage payment calculator
The biweekly trick is calendar arithmetic: half your monthly payment every two weeks is 26 half-payments a year — thirteen monthly payments dressed as twelve. That quiet extra payment goes entirely to principal. On the example $300,000 loan at 6.5% below, the biweekly schedule pays off 5 yr 11 mo early and saves $88,123 in interest versus the monthly schedule.
The calculator switches the whole schedule to biweekly mode — every row becomes a dated half-payment — so you see the real mechanics, not a summary estimate. Swap in your own balance and rate; the comparison against monthly payments computes automatically.
Preset: example $300,000 loan in biweekly mode — set your own numbers
Payment-by-payment schedule
| # | Date | Payment | Principal | Interest | Extra | Balance |
|---|
Click a year to expand its payments. Exports and print always include every payment.
How it works
- Open this page — the calculator is already set up for "Biweekly mortgage payment calculator". Swap in your own amount, rate and term.
- Read off the payment, the payoff date and total interest. The full payment-by-payment table is right below.
- Add extra payments or switch to biweekly to watch the payoff date move and the interest saved appear.
- Download the schedule as Excel, CSV or PDF — generated on your device; your loan details never leave your browser.
DIY beats the paid programs
Third-party “biweekly conversion programs” charge enrollment and per-payment fees to do what this page shows for free — and some simply hold your half-payments and forward a normal monthly payment plus one extra per year. You can replicate the entire benefit yourself two ways: genuinely pay biweekly if your servicer supports it, or stay monthly and add one-twelfth of your payment as extra principal each month. The second option needs no servicer cooperation at all and lands within dollars of the true biweekly result — verify that yourself by comparing this page against the extra-payments page with your payment ÷ 12 as the extra.
One caution from the fine print: some servicers hold partial payments in suspense until the second half arrives, which recreates the monthly schedule with extra steps. Ask how half-payments are applied before committing to the rhythm — and if the answer is “suspense account”, use the extra-principal route instead.
Good to know
- The savings shown come from the extra annual payment, not from paying “faster within the month” — mortgages accrue monthly, so mid-cycle timing doesn’t matter the way it does on daily-interest car loans.
- Biweekly aligns nicely with biweekly paychecks: one half-payment per check, and the two three-paycheck months of the year are exactly where the acceleration comes from.
- Check that your servicer applies half-payments on receipt rather than holding them — if held, use the DIY extra-principal route instead.
Frequently asked questions
How much faster does biweekly really pay off a 30-year mortgage?
It depends on the rate — the effect grows with it. On the example above (6.5%), the payoff moves up by 5 yr 11 mo. At lower rates the time saved shrinks; at higher rates it grows. Enter your own rate above for the exact answer rather than a rule of thumb.
Is there any downside to biweekly payments?
The money is committed — an extra month’s payment a year that you can’t easily un-pay if cash gets tight (unlike the DIY version, which you can pause any month). Paid conversion programs add fees for no mathematical benefit. And if your servicer holds half-payments in suspense, you get the cash-flow awkwardness without the acceleration. The DIY extra-principal route avoids all three.
Why does the calculator show slightly different savings than my bank’s biweekly flyer?
Biweekly modeling has genuine convention choices — when half-payments credit, how the periodic rate is derived (we use the annual rate ÷ 26, the common convention), and how the final payment rounds. Different choices move the result by small amounts; the shape and scale of the savings don’t change. Our methodology page documents the exact conventions so you can reproduce every number.