Biweekly Mortgage Calculator
Biweekly mortgage halves, yearly extra, and 13 payment effect.
What it does
A biweekly plan pays the mortgage with timing instead of discipline. Half payments every two weeks feel like the monthly amount, yet 26 halves quietly add a thirteenth payment each year. That extra lands straight on principal.
The tool above prices the standard case. A $300,000 loan at 6.00 percent for 30 years asks $1,798.65 a month or $899.33 biweekly, which adds about $1,798.78 extra principal a year. Same house, same rate, faster balance drop.
The extra works only when applied correctly. Servicers must credit principal prepayments to principal, and borrowers keep the right to prepay under standard notes. Confirm no prepayment penalty and no setup fee before signing a biweekly program.
Third party biweekly schemes deserve a hard look. Many charge fees for what amounts to one extra payment a year, which free automatic transfers can copy. Run the numbers here, then ask the servicer for free biweekly or extra principal options.
How to use
- Enter the loan principal.
- Enter the annual rate.
- Enter the term in years.
- Read the monthly payment first.
- Read the biweekly half payment.
- Read the extra principal per year.
Formula
- P
- Loan principal in dollars.
- i
- Monthly rate: annual rate / 12.
- n
- Payments count: years x 12.
The biweekly method follows CFPB guidance: half the monthly amount every two weeks makes 26 payments a year, which equals 13 monthly payments. The extra payment lands on principal when the servicer applies it that way. Federal rules recognize billing cycles shorter than a month, including biweekly schedules.
Worked example
Example: $300,000 at 6% for 30 years
Defaults: $300,000 at 6.00% for 30 years. These are also the default values, so the page opens on this answer.
- Loan: $300,000 at 6.00% for 30 years.
- Monthly rate: 0.06 / 12 = 0.005 over 360 months.
- Monthly: $1,798.65.
- Biweekly: 1798.65 / 2 = $899.33.
- Yearly monthly plan: 1798.65 x 12 = $21,583.80.
- Yearly biweekly: 899.33 x 26 = $23,382.58.
- Extra: 23382.58 - 21583.80 = $1,798.78, about one payment.
- Tool shows $1,798.65 monthly with $899.33 biweekly and $1,798.78 extra a year.
Reference table
| Loan | Monthly | Biweekly |
|---|---|---|
| $200,000 | $1,199.10 | $599.55 |
| $300,000 | $1,798.65 | $899.33 |
| $400,000 | $2,398.20 | $1,199.10 |
Limits
- Principal and interest only; no taxes or insurance.
- Assumes fixed rate for the full term.
- Ignores servicer fees and holds.
- Extra must be applied to principal.
Common mistakes
- Paying a fee for a free transfer trick.
- Assuming the servicer auto applies extra.
- Forgetting escrow still bills monthly.
- Quitting early before interest savings build.
- Mixing biweekly with twice a month.
Try it yourself
Quick checks. Answers sit tucked under each question.
$200,000 at 6% for 30 years?
Monthly $1,199.10 with biweekly $599.55 and $1,199.10 extra a year.
$400,000 at 6% for 30 years?
Monthly $2,398.20 with biweekly $1,199.10 and $2,398.20 extra a year.
Questions
How does biweekly work?
Half the monthly payment every two weeks: 26 halves a year equal 13 monthly payments.
Extra per year on the example?
About $1,798.78 a year here, roughly one extra monthly payment toward principal.
Does it shorten the loan?
Yes, when the servicer applies the extra to principal with no prepayment penalty.
Any fees to watch?
Ask the servicer: some charge setup fees or hold partial payments instead of applying them.
All in payment included?
No. Taxes, insurance, rate changes, and fees sit outside this math.
Biweekly or refinance?
Refinance first if the rate drops enough; biweekly and refinancing can combine.