Is a biweekly schedule different from making one extra payment a year?

Mathematically they're nearly identical. Both result in 13 monthly equivalents per year. The biweekly schedule spreads the cash flow more evenly across the year, but the principal-reduction outcome is the same.

Will my lender accept biweekly payments?

Many do. Some only post payments monthly regardless of when they arrive, in which case partial early payments are held in suspense — which means no actual benefit. Check your servicer's policy before assuming.

Is true biweekly amortization on the roadmap?

Yes — a dedicated biweekly mode is on the calculator backlog. For now, the monthly-extra approximation produces the same payoff outcome.

Biweekly mortgage payments

Switching to biweekly payments can shave years off your mortgage — but only if you do it right. Here's the math, the watch-outs, and how to approximate the effect in the calculator.

How biweekly payments work

You pay half your scheduled monthly amount every two weeks. Twenty-six biweekly halves equal thirteen full monthly payments per year — one more than the twelve you'd make on a monthly schedule. That extra payment goes entirely to principal, which compounds into faster payoff and less lifetime interest. On a 30-year loan, the typical effect is 4–6 years off the term.

Important — what this calculator does and doesn't model

Mortgage Well does not currently model true biweekly servicing schedules in the calculator. The amortization engine walks month by month, not every two weeks, so it can't simulate the biweekly rhythm directly.

You can approximate the same payoff effect two ways:

Monthly extra: add an extra principal payment each month equal to (1/12) of your scheduled monthly payment. Twelve of those equal one full extra payment per year — the biweekly result.
Annual extra: add a one-time extra equal to one full scheduled monthly payment, applied once a year.

Both approximations match the biweekly outcome closely enough for planning. A true biweekly amortization mode is on the backlog.

Three ways to actually go biweekly

Servicer-run biweekly program. Some servicers offer a built-in biweekly option, often free. Confirm that the extra half-month per year is actually applied to principal — not held as a future scheduled payment.
Third-party biweekly services. Charge a setup fee plus per- payment fees. They often forward to the servicer monthly anyway, with the "extra" held back as a 13th annual payment. The math you get is usually identical to just paying the 13th yourself — for free.
DIY equivalent. Pay your scheduled monthly amount plus 1/12 of that amount as extra principal each month. Identical math, no fees, no third-party dependency.

Worked example

On a $320,000 loan at 6.5% over 30 years, the scheduled monthly payment is about $2,022. A monthly extra of about $169 (which is 2,022 / 12) approximates the biweekly effect. Cumulative interest savings over the life of the loan: tens of thousands of dollars. Months shaved off the term: typically 4–5 years.

Watch-outs

Don't pay a third party for what you can do yourself. The math is the same; the fees aren't.
Confirm in your statement that the extra is applied to principal. If it's being held as a future payment, call the servicer and have it re-applied.
Don't prioritize biweekly extras over building an emergency fund or capturing employer retirement matches.

Frequently asked

Is a biweekly schedule different from making one extra payment a year?: Mathematically they're nearly identical. Both result in 13 monthly equivalents per year. The biweekly schedule spreads the cash flow more evenly across the year, but the principal-reduction outcome is the same.
Will my lender accept biweekly payments?: Many do. Some only post payments monthly regardless of when they arrive, in which case partial early payments are held in suspense — which means no actual benefit. Check your servicer's policy before assuming.
Is true biweekly amortization on the roadmap?: Yes — a dedicated biweekly mode is on the calculator backlog. For now, the monthly-extra approximation produces the same payoff outcome.

Sources and references

Helpful consumer references used to explain assumptions on this page. These are educational pointers, not regulatory endorsement.

CFPB — biweekly mortgage payment programs — consumer guidance on biweekly programs, including watch-outs for third-party service fees