How to calculate prorated rent
Count the days, choose the denominator, and round at the end. Here is the arithmetic behind a clear partial-month estimate.
Start with four decisions
- Confirm the base rent. Keep deposits, credits and other charges outside this calculation.
- Identify the billable period. Use the dates agreed for billing rather than assuming a physical move date decides the charge.
- Confirm inclusion. Write whether the selected move date counts.
- Select the method. Use the denominator specified for the calculation, then keep it consistent.
You can enter these choices in the prorated rent calculator and compare all three results. The examples below use hypothetical rents and our published conventions, as of October 25, 2026.
Example 1: move in during a 31-day month
Monthly rent is $1,800. Move-in is October 20, 2026, with October 20 included. Count 31 − 20 + 1 = 12 days.
| Method | Calculation | Total |
|---|---|---|
| Actual month | $1,800 ÷ 31 × 12 | $696.77 |
| 365-day year | $1,800 × 12 ÷ 365 × 12 | $710.14 |
| 30-day, capped | $1,800 ÷ 30 × 12 | $720.00 |
The counted dates are identical. The totals differ because each method assigns a different daily rate. None of these example results reaches the 30-day method's monthly cap.
$1,800.00 ÷ 31 × 12 counted days = $696.77.
Brick border: counted days. Mustard outline: selected date.
Example 2: move out, with the date excluded
Monthly rent is $1,500. Move-out is June 10, 2026, and the agreement for this example excludes June 10. Count June 1–9: 9 days.
Actual month: $1,500 ÷ 30 × 9 = $450.00
The 365-day method gives $1,500 × 12 ÷ 365 × 9 = $443.84. The fixed 30-day method gives $450.00. Including June 10 would add one day to every calculation, producing $500.00, $493.15 and $500.00 respectively.
Example 3: February in a leap year
Take hypothetical rent of $1,800 and a move-in date of February 20, 2028, including that day. February 20–29 contains 10 days.
Actual month: $1,800 ÷ 29 × 10 = $620.69
The 365-day method still uses 365, giving $591.78. The fixed 30-day method gives $600.00. This tool deliberately distinguishes a calendar-sensitive monthly denominator from a fixed annual denominator.
The full-month boundary is revealing
For all 31 days of October at $1,800 rent, actual-month proration returns $1,800.00. The uncapped 365-day formula returns $1,834.52. Our 30-day method first calculates $1,860, then caps it at $1,800.00.
For all 28 days of February 2026, the actual-month method returns $1,800, but the fixed 30-day formula returns $1,680. That is why this page describes the 30-day option as a specific calendar-day convention rather than a universal billing rule. If your agreement treats a full month as one regular payment, use that payment and reserve proration for the eligible partial period.
Keep an audit trail
A useful note records the monthly rent, calendar dates, inclusion choice, denominator, unrounded calculation and rounded final amount. For example: “October 20–31 inclusive, 12 days; $1,800 ÷ 31 × 12; $696.77.” That sentence is easier to verify than a total without assumptions.
Read the methodology for input limits, date handling and rounding. If a result looks wrong, send a correction request with non-sensitive example inputs.
Questions, answered
How is prorated rent calculated?
Under the actual-month method, divide monthly rent by the calendar days in that month, then multiply by the billable days. At $1,800 for a 30-day month, 10 billable days cost $600. The annual and capped 30-day methods use the different formulas shown above.
How do I figure out prorated rent for my move date?
Confirm the monthly rent and agreed method, decide whether the move day is billable, then count the relevant dates. For move-in, count toward month-end; for move-out, count from the first. Keep the daily rate unrounded until calculating the final charge.
Should I round the daily rate before multiplying?
This calculator keeps the daily rate unrounded during the calculation and rounds the final charge to cents. Rounding the daily rate first can change the total. If your agreement specifies a rounding convention, follow that convention.
How are leap years handled?
Actual-month proration uses 29 days for February in a Gregorian leap year. The 365-day method deliberately keeps a denominator of 365 even in a leap year. These are separately defined methods.
How do I handle a period across two months?
This calculator handles one calendar month at a time. Calculate each partial month separately using the agreed method, then add the amounts. Do not silently extend an actual-month daily rate from one month into another.
Sources & calculation notes
As of October 25, 2026. Numerical examples are hypothetical calculations using our published formulas and conventions, not quotes or legal limits.
- USAGov: Tenant rights — Starting point for finding state tenant-rights and complaint resources. This calculator does not determine legal obligations.
- U.S. Naval Observatory: Calendars — Background on the Gregorian calendar. Our date arithmetic uses Gregorian month lengths and leap years.