Biweekly Loan Payment Calculator
Making half your monthly payment every two weeks rather than a full payment once a month results in 26 half-payments per year, equivalent to 13 full monthly payments instead of 12. The extra annual payment reduces your principal faster, which lowers the interest charged each subsequent period and shortens the loan term. This strategy requires no extra monthly budgeting: you simply pay more frequently. Enter your loan details to see how much you save in interest and how many months you eliminate from your loan term.
Biweekly payment formula
Monthly M = P*r*(1+r)^n / ((1+r)^n-1). Biweekly = M/2 paid 26 times/year (= 13 months/yr). Simulate biweekly with biweekly rate r14 = APR*14/365 applied every 2 weeks.
For the biweekly simulation, the biweekly interest rate is APR * 14/365. Each period: interest accrues at that biweekly rate, and the half-payment is applied. The effective annual payment is M/2 * 26 = 13M rather than 12M.
How biweekly payments work in practice
The simplest way to implement biweekly payments is to divide your monthly payment by 12 and add that amount to each monthly payment. This is mathematically equivalent to making 13 monthly payments per year. Some servicers accept true biweekly payments; others may hold funds until the end of the month. Confirm with your servicer that extra payments are applied to principal immediately, not held as a future scheduled payment.
Frequently asked questions
How do biweekly payments save money?
By making half of your monthly payment every two weeks, you make 26 half-payments per year, which equals 13 full monthly payments instead of 12. The extra payment each year reduces your principal faster, cutting interest and shortening the loan term.
What is the difference between biweekly and semi-monthly payments?
Biweekly means every two weeks: 26 payments per year (13 full months). Semi-monthly means twice per month: 24 payments per year (12 full months). Only biweekly provides an extra effective payment per year. Semi-monthly is equivalent to monthly in terms of total annual payment.
How much can I save on a mortgage with biweekly payments?
On a 30-year mortgage at a typical rate, switching to biweekly payments can save several years off the loan term and tens of thousands of dollars in interest. The exact savings depend on the loan balance, rate, and how early in the loan term you switch.
Do all lenders allow biweekly payments?
Not all lenders offer or support biweekly payment programs natively. Some charge fees for biweekly arrangements. A free alternative is to make one extra payment per year by dividing your monthly payment by 12 and adding that amount to each monthly payment.
Are there tax implications of paying off a mortgage faster?
Paying less total mortgage interest reduces the potential mortgage interest deduction on your federal taxes (for itemizers). However, the out-of-pocket interest savings almost always outweigh any tax benefit, since you only deduct at your marginal tax rate.
Official sources
- CFPB: Mortgages.
- Federal Reserve Consumer Credit G.19: Consumer Credit Release.
Reviewed by the CalculatorHub team, edited by James Graham, 15 June 2026. See our methodology.