Biweekly mortgage calculator
Paying half the monthly payment every two weeks means 26 half-payments a year — one extra monthly payment. See what that saves.
Assumes the extra payment is applied to principal immediately.
How this calculator works
A standard mortgage has 12 monthly payments a year. Paying half the monthly amount every two weeks gives 26 half-payments — 13 full payments — so you make one extra payment a year, and each extra payment goes entirely to principal. The effect compounds: most 30-year mortgages finish about 4–6 years early.
You do not have to use a biweekly programme: making one extra monthly payment a year, or adding 1/12 of your payment to each month, has nearly the same effect without the fees some lenders charge for biweekly setups.
The formula
monthly payment = P × r ÷ (1 − (1 + r)^−n)
biweekly payment = monthly payment ÷ 2
effective monthly payment = biweekly × 26 ÷ 12Worked example
On a 300,000 loan at 6.50% for 30 years, the monthly payment is $1,896.20 and the biweekly payment is $948.10. Biweekly payments save $87,256.29 in interest and cut 5.8 years off the term.
Common mistakes
- Paying a setup fee. Third-party biweekly services charge for something you can do yourself by adding 1/12 to each monthly payment.
- Letting the lender hold the half-payments. Some plans debit every two weeks but only apply the payment monthly, which reduces the benefit.
- Forgetting the emergency fund. Extra principal payments are hard to reverse; keep cash reserves first.
Frequently asked questions
Does biweekly really save that much?
It saves the interest on one extra monthly payment a year, compounded — typically 4–6 years and tens of thousands of dollars on a 30-year mortgage.
Is biweekly better than a shorter term?
A 15-year loan usually saves more interest but raises the required payment; biweekly is optional extra principal, so it is more flexible.
Can I just pay extra each month instead?
Yes — adding 1/12 of the payment monthly is equivalent and avoids programme fees.
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