Partial-month rent and charged days
Charged days include both dates. Actual-month mode divides monthly rent by the number of dates in that month; fixed-30 mode divides it by 30. The daily figure is displayed to four decimal places, but the charge uses the unrounded daily rate and rounds only the final amount to cents.
To inspect a longer calendar interval before splitting it into months, use the Date Difference Calculator .
The formula
The actual divisor is 28, 29, 30, or 31 according to the Gregorian month. The alternative divisor is always 30, while charged days still follow actual dates. This fixed-divisor mode does not implement a financial 30/360 day-count convention, suppress the 31st day, or cap a charge at monthly rent.
Moving in halfway through October
Monthly rent of 1,500 with charged dates October 16–31, 2026 gives 16 charged days. Actual-month proration is 1,500 × 16/31 = 774.19 after final rounding. Fixed-30 division gives 1,500 × 16/30 = 800.00.
How to use this calculator
- Enter the monthly rent and the currency used in the rental agreement.
- Enter the first and last dates to charge within a single calendar month; both count.
- Choose the daily-rate basis specified for your calculation, then compare the charge and divisor.
Use charged dates rather than guessing from occupancy
A move-in date may be charged while a move-out date may be excluded under a particular agreement. This form always includes both dates, so enter the last date that should actually be charged. A one-day interval produces one daily charge. The tool computes your entered period and basis; it does not decide which dates the parties agreed to bill.
Why a fixed divisor changes the result
In actual-month mode, charging every day of the month reproduces one monthly rent before rounding. A fixed divisor is independent of month length: a full 31-day interval produces 31/30 of monthly rent, while a 28-day interval produces 28/30. Those results are intentional arithmetic, not an automatic rent policy. Select the method that matches the stated arrangement.
Calculate separate months separately
Monthly rent proration can change at a month boundary, especially for February and leap years. This tool requires both dates to lie in the same month so the denominator stays clear. For a period spanning multiple months, calculate each partial month separately and account for complete months according to the agreement. Deposits, utilities, service charges, and unpaid balances are additional items.
Assumptions & limitations
What this calculation assumes
- Both entered dates are charged; one monthly rent and one divisor apply.
- Final rent is rounded half-up to two decimal places; intermediate daily rates are retained.
What to keep in mind
- Single-month intervals only, with valid dates from 1900 through 2100.
- Fixed-30 mode has no cap, no day-31 adjustment, and no 30/360 convention.
- No jurisdiction-specific rental rules, lease interpretation, taxes, deposits, or recurring-fee allocation.
Common questions
Does the move-in day count?
The first charged date counts. Enter the date from which rent should be charged under your arrangement.
How is leap-year February handled?
Actual-month mode uses 29 days in a leap year and 28 otherwise. Fixed-30 mode retains a divisor of 30.
Why does multiplying the displayed daily rate differ by a cent?
The displayed daily rate is rounded to four decimals. The final charge uses its unrounded value, so multiplying the shortened display can produce a different rounding result.