Bi-Weekly Mortgage Payment Calculator
Switch from monthly to bi-weekly mortgage payments and you make one extra full payment every year, which can shave years off your loan and save tens of thousands in interest. Enter your loan details below to see your bi-weekly payment, the interest saved, the time cut from your term, and a side-by-side comparison. An optional extra-payment field lets you model lump-sum accelerations on top of the bi-weekly schedule.
How bi-weekly mortgage payments work
A bi-weekly mortgage payment schedule splits your standard monthly payment in half and requires you to pay that amount every two weeks. Because a year has 52 weeks, you end up making 26 half-payments, which equals 13 full monthly payments rather than the 12 you would make on a standard schedule. That one extra payment goes entirely toward reducing your principal balance, which shrinks the base on which interest accrues every subsequent period. The compounding effect of that annual boost to principal paydown grows over time, so the savings accumulate faster in the back half of a long-term loan.
How to calculate your bi-weekly payment
Start with the standard monthly payment formula: P = A x r x (1+r)^n / ((1+r)^n - 1), where A is the loan principal, r is the monthly interest rate (annual rate / 12), and n is the total number of monthly payments. Divide the resulting monthly payment by 2 to get your bi-weekly amount. This calculator uses actual bi-weekly amortization (rate / 26 per period) rather than simply dividing the monthly figure, which produces more accurate payoff dates. The "true" bi-weekly schedule slightly changes each period's interest split because the period length (14 days) does not line up perfectly with a calendar month.
Setting up bi-weekly payments correctly
There are three common ways lenders handle bi-weekly payments. The first is an automatic program where the servicer drafts half your payment every two weeks and applies the extra half-payment directly to principal at the end of each year. The second is a third-party accelerated payment program, which typically charges setup and maintenance fees that can easily consume years of interest savings. The third, and usually best, approach is to make the extra payment yourself: continue paying monthly, then make one additional full principal-only payment each year, or pay 1/12 of your monthly payment on top of each monthly payment. All three methods achieve essentially the same payoff acceleration, but the self-directed approach costs nothing in fees.
Extra payments on top of bi-weekly
Stacking an additional principal payment on top of the base bi-weekly amount compounds the acceleration effect. Even a modest extra $50 per bi-weekly period adds up to $1,300 per year toward principal. On a 30-year $300,000 loan at 6.75%, that can reduce total interest by an additional $20,000-plus and cut another year or two off the payoff date. Use the extra payment field in this calculator to model any additional amount and see the precise combined impact.
How bi-weekly payments compare across common loan scenarios
| Rate | Term | Monthly payment | Bi-weekly payment | Interest saved | Years saved |
|---|---|---|---|---|---|
| 5.00% | 30 yr | $1,610 | $805 | ~$34,000 | ~4.5 |
| 6.00% | 30 yr | $1,799 | $900 | ~$47,000 | ~4.8 |
| 6.75% | 30 yr | $1,946 | $973 | ~$57,000 | ~5.1 |
| 7.00% | 30 yr | $1,996 | $998 | ~$62,000 | ~5.2 |
| 5.00% | 15 yr | $2,372 | $1,186 | ~$12,000 | ~2.0 |
| 6.00% | 15 yr | $2,532 | $1,266 | ~$16,000 | ~2.1 |
| 6.75% | 15 yr | $2,654 | $1,327 | ~$19,000 | ~2.2 |
Estimated interest savings and time saved on a $300,000 loan at the stated rate, switching from monthly to bi-weekly payments. Actual results vary.
Frequently asked questions
Does my lender have to allow bi-weekly payments?
Not all servicers formally offer a bi-weekly program. However, most will accept extra principal payments at any time. A practical workaround is to continue making your regular monthly payment and then submit one extra principal-only payment each year equal to one full monthly payment. The result is mathematically identical to a formal bi-weekly plan and typically costs you nothing.
Why does bi-weekly save more than just one extra payment per year?
While the net cash out of pocket is the same as making 13 monthly payments, the timing matters. With true bi-weekly payments you reduce the balance slightly every two weeks rather than every month, so each period's interest accrues on a marginally lower balance. The cumulative effect of that slightly smaller interest charge every 14 days produces modestly more savings than a single lump-sum extra payment made at year-end.
Will bi-weekly payments hurt my credit score?
No. Paying more frequently and paying down your principal faster generally has a neutral or slightly positive effect. Your mortgage servicer still reports your account as current to credit bureaus on the standard monthly cycle. Paying ahead of schedule does not create any negative marks.
What is the difference between bi-weekly and semi-monthly payments?
Semi-monthly means twice per calendar month, which produces exactly 24 half-payments (12 full payments) per year, the same as monthly. Bi-weekly means every 14 days, which produces 26 half-payments (13 full payments) per year. Only the bi-weekly schedule generates the extra 13th payment that accelerates payoff. Semi-monthly payments offer cash-flow convenience but no interest savings over a standard monthly plan.
Does this calculator account for taxes and insurance (escrow)?
No. The payment figures here cover only principal and interest. If your lender escrows property taxes and homeowners insurance, your actual payment will be higher by the monthly escrow amount. The interest-savings calculation is unaffected by escrow because taxes and insurance are pass-through costs that do not change with payment frequency.
Can I switch to bi-weekly payments on any mortgage type?
Bi-weekly payment acceleration works on fixed-rate and adjustable-rate mortgages. For an ARM, the savings projections shown here assume the current rate holds for the life of the loan; if your rate resets, your actual savings will differ. FHA, VA, and USDA loans can all be paid bi-weekly as long as your servicer accepts extra principal payments, which they are required to by federal regulation.