Mortgage Payoff Calculator

How This Calculator Works

Paying half your mortgage payment every two weeks instead of the full payment once a month adds up to one extra full payment every year — and can shave years off your payoff time. Enter your current remaining balance, rate, and remaining term, and this calculator compares your standard schedule against switching to biweekly payments, with an optional one-time extra payment on top.

A year has 52 weeks, so paying every two weeks means 26 payments a year — at half your normal monthly payment each time, that works out to 13 full monthly payments’ worth annually instead of 12. That extra payment goes straight to principal, which is why biweekly payments pay off a mortgage faster and save real money in interest, without requiring a bigger monthly budget than you’re already used to.

This is deliberately distinct from the Mortgage Calculator‘s own extra-monthly-payment feature: that answers “what if I add a flat amount to my payment every month,” while this answers “what if I switch payment frequency entirely, starting from where my existing mortgage stands today.”

The Formula

The biweekly schedule is simulated directly: $\text{Biweekly Payment} = \vA{\text{Standard Monthly Payment}} \div 2$, applied every two weeks at a period interest rate of $\vB{\text{Annual Rate}} \div 26$, continuing until the balance reaches zero.

Worked Example

A $250,000 remaining balance at $\vB{6\%}$, with 300 months (25 years) left on the standard schedule:

1. Standard monthly payment: $\vA{\approx \$1{,}610.75}$, paying ≈ $233,226 in total interest over the remaining term.
2. Biweekly payment: $\vA{1{,}610.75} \div 2 \approx \$805.38$, paid every two weeks at a period rate of $\vB{6\%} \div 26 \approx 0.023\%$.
3. Switching to biweekly payments pays off the loan in about 252 months (21 years) instead — nearly 4 years faster.
4. Total interest under the biweekly schedule: ≈ $190,235 — a savings of about $42,991.