Hong Life CalculatorsUnderstanding the prorated rent calculator — concept and principle
When you move in or out partway through a month, you usually pay rent only for the days you occupy the home. This calculator works out that prorated rent using the method your lease specifies and shows when the first full rent is due.
How it is calculated
- Daily rate, by method: monthly rent ÷ days in that month (most common), yearly rent ÷ 365, or monthly rent ÷ 30 (a "banker's month").
- Days charged: counting both the move-in (or move-out) day and the other end of the period.
- Prorated rent = daily rate × days charged, never more than one full month.
- Share of a full month = days charged ÷ days in that month.
The principle
Rent accrues day by day, so a part month is a fraction of a full month. Using the actual number of days in the month makes the daily rate a little different in February than in a 31-day month; the 365-day method gives the same daily rate all year; the 30-day method is simple but can slightly overcharge or undercharge. The lease decides which method applies.
Worked example
Default inputs: monthly rent 1,500 USD, moving in on 22 November 2026, actual days in the month.
- November has 30 days, so the daily rate = 1,500 ÷ 30 = 50.00 USD.
- Days charged from 22 to 30 November inclusive = 9.
- Prorated rent = 50.00 × 9 = 450.00 USD, or 30% of a full month.
- The first full rent is due on Tue, Dec 1, 2026.
| Monthly rent | Prorated rent |
|---|---|
| 375 | $112.50 |
| 750 | $225.00 |
| 1,125 | $337.50 |
| 1,500 | $450.00 |
| 1,875 | $562.50 |
| 2,250 | $675.00 |
| 3,000 | $900.00 |
How to read the result
Check the lease to confirm the method and whether the move-in day is counted. Some landlords collect the prorated amount with the first full month; others ask for it at signing. If you move out, confirm whether notice periods require you to pay through the end of a month regardless of when you leave.
Common mistakes
- Forgetting to count the move-in day itself.
- Using 30 days for every month when the lease says actual days.
- Assuming you can prorate move-out rent when the lease requires full-month notice.
- Mixing up prorated rent with the security deposit.
Frequently asked questions
How do I calculate prorated rent?
Divide the monthly rent by the days in the month and multiply by the number of days you occupy the home.
Is the move-in day included?
Usually yes, because you have use of the home that day; check your lease.
Which method gives the lowest rent?
It depends on the month. In a 31-day month, actual days give a lower daily rate than the 30-day method.
Sources: US Department of Housing and Urban Development, Occupancy Requirements of Subsidized Multifamily Housing Programs (Handbook 4350.3), proration guidance · 주택임대차보호법 (임대차 계약 일반)