Biweekly vs Monthly Payment Calendar Calculator
Compare actual payment dates, annual cash budgets and accrued payoff balances under one daily-interest convention.
Your inputs
Use consistent units and periods. Defaults are examples.
Your result
Check the assumptions below before relying on a result.
Formula and method
Reference monthly payment uses the ordinary annuity formula. All dated comparisons accrue noncapitalized simple interest = principal × annual rate × actual elapsed days/365. Payments first clear accrued interest, then principal. Monthly dates preserve the start-day anchor and clamp to month end. Biweekly dates occur exactly every 14 days; semi-monthly dates are the 1st and 15th. Horizon payoff = principal + interest accrued since the last payment.
Worked example
For 10,000 at a 36.5% daily simple rate, January 1 to January 15 accrues 140 interest. A 500 payment then reduces principal to 9,640. Another 14 days accrues 134.96; the next 500 reduces principal to 9,274.96. The example isolates daily arithmetic; the tool’s rate input is capped at 30% for practical scenarios.
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Open calculator ↗How to use this result
- Choose a starting date and the same comparison horizon for every schedule.
- Inspect the actual event dates and number of payments rather than assuming 26 every calendar year.
- Compare actual cash paid separately from remaining principal and accrued interest.
- Ask the lender how half payments are handled before interpreting this daily model as a servicing result.
Questions about this calculation
Are twice-monthly and every two weeks the same?
No. Twice-monthly uses two selected days per calendar month. Every 14 days moves through the calendar and can produce 27 payments in some calendar years.
Does annual-budget mode make every option spend exactly the same cash?
No. It scales the every-14-days amount using 26 events per year, but the actual horizon uses the generated dates and capped final payment. The table reports the actual cash.
Why include unpaid accrued interest in the remaining balance?
Ignoring interest accumulated between the last payment and comparison date would make schedules with different dates appear unfairly cheaper.